Mastering GTO Restorations: Engine Guide

All 1964–1974 Pontiac GTOs used some version of what we now refer to as the “traditional” Pon­tiac V-8. It was produced from 1955 through 1979 and a modified version continued for another two years. By the time the GTO rolled around, the Pontiac V-8 had a decade of improvements under its belt and a special version of the venerable 389 was developed for use specifically in the GTO. It featured cylinder heads from the 421 HO and a special cam­shaft designed to provide additional top-end power. Both 4-barrel and Tri-Power versions were offered with horsepower ratings of 325 and 348, respectively.

 


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Achieving a factory-correct engine restoration with all stock equip¬ment and finishes is no small feat, but it’s something you can cer¬tainly accomplish. Unless your GTO is 100-percent complete and original, it may take some time to get all the required parts. With some research, patience, and skill, you can get it all “correct.” In the case of this 1969 GTO convertible, no expense has been spared to correctly restore this engine and the engine compart¬ment; it’s as close to perfection as any. The engine paint, valve covers, air cleaner, accessories, hose clamps, and other equipment are all correct. But the restorer didn’t stop there; the date codes on the hoses, belts, and plug wires are correct for the build date of the car.  An engine restoration for a pedigree Tri-Power, Ram Air IV, Judge, or other rare GTO is well deserved. You may not want to make this investment in a pedestrian 1969 GTO 400 2-barrel automatic because you won’t recoup the investment from selling the car. In addition, the level of engine restoration should be determined by your personal taste, its intended use, whether your car is numbers-matching and of course, your budget. A daily-driver engine can be restored to the region of 75-percent correct and appear similar to stock. After all, it doesn’t take a lot of money to make an attractive engine compartment, but making it 100-percent correct does. (Photo Courtesy Scott Tiemann)

Achieving a factory-correct engine restoration with all stock equip¬ment and finishes is no small feat, but it’s something you can cer¬tainly accomplish. Unless your GTO is 100-percent complete and original, it may take some time to get all the required parts. With some research, patience, and skill, you can get it all “correct.” In the case of this 1969 GTO convertible, no expense has been spared to correctly restore this engine and the engine compart¬ment; it’s as close to perfection as any. The engine paint, valve covers, air cleaner, accessories, hose clamps, and other equipment are all correct. But the restorer didn’t stop there; the date codes on the hoses, belts, and plug wires are correct for the build date of the car.
An engine restoration for a pedigree Tri-Power, Ram Air IV, Judge, or other rare GTO is well deserved. You may not want to make this investment in a pedestrian 1969 GTO 400 2-barrel automatic because you won’t recoup the investment from selling the car. In addition, the level of engine restoration should be determined by your personal taste, its intended use, whether your car is numbers-matching and of course, your budget. A daily-driver engine can be restored to the region of 75-percent correct and appear similar to stock. After all, it doesn’t take a lot of money to make an attractive engine compartment, but making it 100-percent correct does. (Photo Courtesy Scott Tiemann)

 

As the years passed, displace­ments and horsepower ratings increased the base 389 grew to 400 ci, with new, freer-flowing cyl­inder heads. Optional round-port heads debuted in the 1968 Ram Air II. A 370-hp Ram Air IV was intro­duced for the 1969 and 1970 model years. An optional 455-ci engine also entered the line-up in 1970. A low-compression 455 HO replaced the Ram Air IV in 1971 and both the 400 and 455 remained in vari­ous versions until 1974 when they were replaced with a new 4-barrel version of the 350, which was used for just one year. It was rated at 200 net horsepower.

Time for a Rebuild?

The engine currently in your GTO may or may not be the original engine that was installed at the fac­tory. Perhaps your car came without an engine altogether. Whatever your situation, this is a great time to build a Pontiac engine. Why? Because you can benefit from a level of after­market support for the Pontiac V-8 engine that is truly remarkable. My intention is to outline some ideas for rebuilding your engine to take advantage of this support while still maintaining the spirit of the original.

As street performance engines, Pontiac V-8s were among the best available. They boasted a generous displacement, fantastic low- and mid-range torque, and a responsiveness that left many race-inspired mills at the starting line. For the street racing movement of the 1960s and 1970s, most “competition” was stoplight to stoplight, so a big, torquey V-8 like a 400 or 455 Pontiac with a lot of low-end grunt was the usual winner in a short distance over a more high-strung engine like a Boss 429 or a 426 Hemi. Give either of those engines another block to rev up, and it was a different story.

This 389 Tri-Power from a 1965 GTO is ready to be disassembled and rebuilt. Visually examine the block and look for any cracks or damage in the cast¬ing. Look for any carbon deposits between the block and the head because that could indicate a head gasket failure. That could mean there’s serious inter¬nal engine damage, such as scored pistons and cylinder walls. In addition, look at the intake and exhaust manifolds for any cracks, breaks, or other obvious damage.  As part of any inspection process, you should Magnaflux the block, heads, intake, and exhaust manifolds to ensure they’re free of damage. The process identifies cracks and other deformations that are not obvious to the naked eye. Before turning any wrenches, generously apply penetrating oil on all bolts, so you’re able to remove them without stripping them. Here, the casting number-77 cylinder head stamping is clearly visible on the number-2 (front) exhaust port. Most years have the head casting number on the center exhaust ports. (Photo Courtesy Scott Tiemann)

This 389 Tri-Power from a 1965 GTO is ready to be disassembled and rebuilt. Visually examine the block and look for any cracks or damage in the cast¬ing. Look for any carbon deposits between the block and the head because that could indicate a head gasket failure. That could mean there’s serious inter¬nal engine damage, such as scored pistons and cylinder walls. In addition, look at the intake and exhaust manifolds for any cracks, breaks, or other obvious damage.
As part of any inspection process, you should Magnaflux the block, heads, intake, and exhaust manifolds to ensure they’re free of damage. The process identifies cracks and other deformations that are not obvious to the naked eye. Before turning any wrenches, generously apply penetrating oil on all bolts, so you’re able to remove them without stripping them. Here, the casting number-77 cylinder head stamping is clearly visible on the number-2 (front) exhaust port. Most years have the head casting number on the center exhaust ports. (Photo Courtesy Scott Tiemann)

 

The Pontiac engines are street-oriented performance engines, while the Boss 429 and 426 Hemi are race-oriented engines used on the street. General Motors left sanctioned rac­ing in 1963, so only street perfor­mance could be offered. For that purpose, the Pontiac V-8 fit the bill admirably.

Today, those same characteristics of responsive street performance can be easily integrated into your GTO and substantially upgraded, whether it is for a restoration-style build or something a little hotter. Better bottom-end componentry, freer-breathing heads, computer-designed camshaft profiles, and more efficient exhaust systems can greatly increase power and reliability without disrupting the external appearance of your engine.

Aftermarket Resurgence

Over the past 20 years or so, the popularity of the muscle car move­ment generated a lot of interest in Pontiac engines. After all, they pow­ered the GTO, the original muscle car. The aftermarket responded, first with intake manifolds, then cylin­der heads, then a Pontiac-based race block, then forged-steel stroker kits all amazing developments, consider­ing they are currently supporting an engine family that has been out of OEM production for three decades. In fact, it is now possible to build an entire Pontiac V-8 engine in displace­ments of 600-or-more cubic inches without using a single original part. This is further proof that while there aren’t any new Pontiacs being made anymore, there is a very strong and loyal fan base, which helps keep interest and values up.

If you are considering an engine rebuild, I assume you are not looking to build a mega-dollar race engine for your Goat. Instead, you probably already have an engine that will be pressed into service for this project, and you are looking for something reliable, powerful, and not straying too far from what the Pontiac engi­neers envisioned.

What if I told you that your 389 could become a 453, your 400 a 468, or your 455 a 474, all while still look­ing 100-percent stock and not cost­ing significantly more than a stock rebuild? It is all possible from the magic of a stroker kit. By retaining the standard production Pontiac engine block with nothing more than a standard prep and clean-up overbore, the addition of a new bal­anced rotating assembly with forged pistons and rods and your choice of a cast or forged 4.25-inch stroke crankshaft, you can reap the benefits of up to a 1/2-inch stroke increase with much more durability than the stock cast pieces.

If you add a set of free flowing heads and a more aggressive cam­shaft, you could easily put out 525 or more completely streetable horse­power and have an engine that really lives up to the legendary status of the GTO. Several reputable com­panies can help you find the right combination for your specific block, including Butler Performance and SD Performance.

Throw Out the Stock Pistons and Rods

Even if you aren’t planning on a big jump in displacement, there is no longer any reason to reuse the stock cast connecting rods (PN 541000) in your Pontiac V-8. While they are fine for driving to the grocery store, they should not be considered high-performance items, even though they were installed in all factory GTO engines. Why build in a weak link? By the time you rebuild them and add new bolts, you could buy brand-new forged-steel connecting rods that are light years ahead of the production pieces in terms of strength and overall durability. Yes, you can purchase new forged steel connecting rods for under $300, so why use the stockers?

The same goes with pistons. There are so many good forged pis­tons now that a stock-style cast piston is not worth bothering with. Prices have dropped over the past several years, while quality and selec­tion have improved.

The truth is, most engines being rebuilt for stock restorations are not stock on the inside and that is a good thing. With inexpensive and, more importantly, superior-quality inter­nal parts being manufactured these days, most purists have come around on aftermarket pieces. If you can build more strength, durability, and reliability into your restorations and save money while doing so, it is fool­ish to rely on inferior, metal-fatigued originals.

Identifying an Engine

The Pontiac V-8’s high level of interchangeability did wonders to reduce production costs over the years, and it also went a long way to help shade-tree mechanics get their cars back on the road after a major failure. With an afternoon’s worth of work a blown-up 389 could be replaced with a later 350, 400, or 455. This could quickly put an ail­ing car back in service, but this ease of swapping engines also made for a lot of non-original GTOs. Add to that the fact that many blown-up factory engines were replaced under warranty with service replacement blocks, and finding an original, numbers-matching GTO is not easy. Fortunately for us, this is not a para­mount concern but if you are inter­ested in finding out whether the engine sitting between the frame rails of your GTO is the factory-installed original, read on.

Identifying a Pontiac engine is not difficult. What becomes signifi­cant to many restorers is whether the original engine is still in the car. How that is determined is by a care­ful examination of the various codes on the engine’s major castings.

Check the engine ID number against the VIN to determine if you have a numbers-matching car. If you do, it’s much more valuable. However, even if you don’t, that doesn’t mean the car isn’t worth restoring. A GTO with a replacement service engine, a different Pon¬tiac V-8, or a crate engine is certainly worth restor¬ing, but it’s just not going to be worth as much.

Check the engine ID number against the VIN to determine if you have a numbers-matching car. If you do, it’s much more valuable. However, even if you don’t, that doesn’t mean the car isn’t worth restoring. A GTO with a replacement service engine, a different Pon¬tiac V-8, or a crate engine is certainly worth restor¬ing, but it’s just not going to be worth as much.

The following is information about the casting numbers of engines originally available in GTOs from 1964–1974. Obviously, Pontiac listed many other codes for other appli­cations, but these are the ones that GTOs originally came with. Also, keep in mind that codes were re-used and could have completely different applications assigned to them. This is why these codes all have to be cross referenced against the date code and the block casting number. Otherwise, you cannot verify the engine’s fac­tory configuration. For example, the code YS could be a base-engine 389 4-barrel used with a 2-speed auto­matic or a 1970 400 Ram Air III used with a 3-speed automatic.

Block Casting Number

This number is found at the rear of the block. For the 1965 through early 1967 model years, the date code and casting number were both located near the distributor hole. From March 1967 on, the casting number moved to the area between the number-8 cyl­inder (passenger side) and the transmission/bellhousing mount points. For the purposes of identifying origi­nal engines, this book lists the correct block casting numbers for original engine installations for 1964–1974 GTOs. If your casting number does not appear in the list, it is almost cer­tainly not an original engine.

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The engine’s casting codes provide a lot of information. Casting number 9778789 is used for all 1965 389s regardless of final installation. The arrow on the clock icon points to 2 o’clock, and the arrow just below it points to the “D.” The “B205” code is the date; B for February, 20 for the day, and 5 for the year. If it were cast on February 1, 1965, the code would read B15, as no third digit would be used.The date code and arrows are easier to see on the close-up after painting. (Photos Courtesy Scott Tiemann)

The engine’s casting codes provide a lot of information. Casting number 9778789 is used for all 1965 389s regardless of final installation. The arrow on the clock icon points to 2 o’clock, and the arrow just below it points to the “D.” The “B205” code is the date; B for February, 20 for the day, and 5 for the year. If it were cast on February 1, 1965, the code would read B15, as no third digit would be used.The date code and arrows are easier to see on the close-up after painting. (Photos Courtesy Scott Tiemann)

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Block Date Code

The date code is represented by a letter, followed by two or three num­bers. The letter designates the month of the casting A is January, B is Feb­ruary, etc. The next one or two num­bers representthe day of the month. Days before the tenth are usually not given a placeholder zero. The last number represents the year, the year of the casting date, not necessarily the model year. An early 1964 GTO may have a late 1963 build date, and if so, the engine casting date reflects that.

The engine date usually pre-dates the build date of the car (as seen on the cowl tag) by as much as six weeks, though that is certainly not an abso­lute. In some unusual cases, when bodies were put in storage weeks in advance, the engine casting date could be later than the build date on the cowl tag. Blocks may also tell you whether they were cast during the day or night shift and in some years they also list the hour with a clock cast in.

Block Code and Engine ID Number

Block codes and engine ID num­bers are found on a machined pad on the front passenger side of the block, next to the water pump housing, just below the leading edge of the cylin­der head. In most cases, the block VIN and the vehicle VIN were the same, but by late 1967, the block VIN was revised. It started out with a 2 (for Pontiac), the last digit of the year, and a letter for the assembly plant fol­lowed by the last 6 digits of the vehicle VIN. The block code is a two or three-character stamping that identifies the engine version, the transmission, and sometimes other information, such as air conditioning, California, or high-altitude delivery zone.

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Cylinder Head Casting Number

This number is usually a raised cast-in number or alpha-numeric code located on the center exhaust port of the cylinder head. In the 1965 GTO, the code was on the far right exhaust port, viewing the head from the exhaust side. Date codes are also used on cylinder heads and intake manfolds, following the same coding system. This can be helpful determining whether the heads are original to the block.

Other Information Sources

If your engine doesn’t appear on any of these lists, or appears but is in the wrong year, there are other resources that can help you identify them. Wallaceracing.com has a list of engine codes for all years of the Pontiac V-8. I would be remiss if I didn’t mention Pete McCarthy’s fan­tastic book on Pontiac engines, Pon­tiac Musclecar Performance 1955–79. If you really want to know about the traditional Pontiac V-8 history, this is one-stop shopping. When I was on staff at High Performance Pontiac, my colleague Bart Orlans nicknamed it, “The second book of Pete.”

For updated information on mod­ern assembly techniques and compo­nents, Rocky Rotella’s CarTech book, How to Rebuild Pontiac V-8s, is an authoritative guide on the subject.

Choosing a Machine Shop

Selecting a machine shop to han­dle the preparation of your Pontiac engine is a little easier said than done, though with the addition of some common sense, you will be able to make the right decision. Just because your friend had good luck with a shop that bored out his 350 Chevy, doesn’t necessarily mean that it’s the shop for you. It also doesn’t necessar­ily rule it out either.

Word of mouth is, in my esti­mation, the best way to find a good machine shop in your area. In years past, I have had good luck by going into the pits at a drag strip and talk­ing to Pontiac racers about their engine builds and who did their machine work. Time and time again, I was able to pick out one or two good shops within a 100-mile radius.

Today, finding that sort of infor­mation is another reason to be on the Internet. Logging onto the various Pontiac message boards and starting a discussion thread like “Looking for a good Pontiac machine shop in Kan­sas,” usually gets the names of com­panies that can do the job. It’s also a good idea to check with Pontiac parts suppliers for their recommendations. Places like Butler Performance or SD Performance also pass along the names of customers in your area who will agree to talk to you for recom­mendations. This is also one of the great things about the Pontiac hobby that you will come to appreciate the people are great, and most are more than happy to help out a fel­low Pontiac enthusiast and/or owner.

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Once a shop has been chosen, be sure to talk to them in detail about what you want done and what you do not want. Have them walk you through the entire process you are paying for from beginning to end. The idea is to avoid any surprises, such as decking the engine and hav­ing all of the factory-stamped infor­mation obliterated. If that happens, the block ID that makes your car a numbers-matching example has been ruined and the car is worth dramatically less. Will they be hot-tanking the engine? How many steps does a clean-up overbore entail? How are valve jobs done? Will they be installing hardened valve seats? Will the combustion chambers be cc’d?

Once the ground rules have been laid down and a price is agreed upon, be sure to photograph every marking on every piece that you are sending off to be machined. It wouldn’t hurt to mark your pieces on a non-visible and unmachined area and let them know that you did so. Show them the marks so they can keep track of your items.

Repair or Replace?

Just as with the rest of the car, once an engine is apart, some sur­prises can pop up, even in a running engine. When parts are Magnafluxed, sonic-tested, and pressure-checked, problems can arise. Remember, you are dealing with castings and rotating assemblies that were built during the Johnson and Nixon administrations. Many components and problems could have occurred over the ensuing years. Maybe it was that overheating back in 1981 or that time it was over-revved in a street race in 1986 that did it in. In any event, the decision has to be made repair or replace?

If you do happen to have an orig­inal, numbers-matching GTO, there is no doubt your overall investment is enhanced by keeping it that way. If that means locating a correct, dated-coded cylinder head to replace the cracked original or tracking down previous owners to see if they still have the original carb, then take the time to do so. You might be surprised with what you find.

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This 1965 GTO and its 389 Tri-Power were restored in the late 1980s. The classic 389 Tri- Power in this car is correct in most areas, which includes the fasteners, hose clamps, and plug wires. However, there is one glar¬ing problem the engine is the wrong color! This Pontiac shade of silver blue was first used in 1966 and lasted through 1970. This is a car of pedigree so all of the finishes should be factory correct, especially the engine-block color. Therefore, this 389 should be repainted in the correct 1965 Pontiac blue paint color. While the engine may have been painted this later color for personal preference (and it does look attractive), most purists see it as a waste of effort. But it would be relatively easy to pull the engine, place it on an engine stand, mask off all the parts, and paint the engine the correct color.

 

Another older restoration, this 1964 has several minor mistakes or non-original equipment items under the hood. These include the belts, hoses, fasteners, and fin¬ishes. The block and manifold are also painted. The master cylinder inspection cover was spray painted gold, which is incorrect but generally presentable and fine for a driver-quality machine.

Another older restoration, this 1964 has several minor mistakes or non-original equipment items under the hood. These include the belts, hoses, fasteners, and fin¬ishes. The block and manifold are also painted. The master cylinder inspection cover was spray painted gold, which is incorrect but generally presentable and fine for a driver-quality machine.

There are also enthusiasts who pull out and store the original drive­line, then build replacements so they can race the car without worry of risk­ing damage to the original engine. Most competitions, such as the annual Muscle Car Shootout in Stan­ton, Michigan, or the Factory Appear­ing Street Tire (F.A.S.T.) Series, do not require an original powerplant. F.A.S.T. allows for a whole host of modifications, while the Muscle Car Shootout requires the cars to be stock and correct. Either way, it is an option that not all builders fully explore.

If the original engine is gone, you actually don’t have the burden of keeping it numbers-matching and you can then explore other avenues. There is one point I want to make perfectly clear: Locating a replace­ment engine does not require it to be an original GTO engine. For exam­ple, let’s say your original YS-coded engine is long gone from your 1966 GTO. You can get almost the same exact engine in a much less expen­sive YE- or YF-coded 389 4-barrel out of a 1966 full-size car.

What are the differences beyond the codes and casting numbers? A slightly milder 066 cam instead of the 067, and 1/4 point of compres­sion, the total of which is 10 hp and 2 ft-lbs of torque less a power level easily recaptured in a performance rebuild and a whole lot more, if you plan ahead.

If you aren’t concerned with the fact that a sharp-eyed Pontiac fan might notice that your cylinder heads say “092” instead of “093,” it is a much more cost-effective way to go. Where a rebuildable, correctly coded engine for a GTO can run in excess of $3,500, a similar engine from a full-size car may be in the $500 to $750 range. Whether the additional cost of a correct engine is worth it is up to the person footing the bill, and that is you. I’m of the opinion that if you build the car the way you want, you will want to keep it. If you build it “for the next guy,” he is the one who will ultimately get the car.

Detailing the Engine

Once the engine is back together, it’s time to paint and detail it to give it an authentic, correct appearance. In addition to the paint, other areas to pay attention to are fasteners, wir­ing, and hoses.

Paint

Ideally, the engine should be painted in the same manner as the rest of the car in a paint booth using a quality paint gun, proper, and safe equipment. If that is not possible, you can still get very pro­fessional-looking results with spray cans. After all, they are simply very compact, one-time use, compres­sor sprayers. But you need to be sure that the surface of the engine is clean, free of grease, and properly prepared. Make sure your painting area does not have contaminants and air flowing through it, which means do not paint your engine in the driveway.

Whether using a spray can or a spray booth, the secret to satisfac­tory results is the preparation of the surfaces. Every little sanding scratch or bit of oil will show up when painted over.

Surface preparation is fairly simple, but time-consuming. If you want it to look right, take the time it deserves. If your engine was at a machine shop, it was likely hot-tanked, but still requires chemical degreasing and a thorough rinsing. After that, a primer coat will indicate any imperfections that need address­ing. Remove all rust before any degreasing takes place.

One area of Pontiac engines that requires a different approach than other V-8 engines is the exhaust port area of the cylinder heads. This area burns off paint very quickly. The reason is because the port has a 135-degree turn, which puts an immense amount of heat just before the port’s exit point right where the casting code is. At car shows you see that area almost always has the paint burned off and rust is starting to form.

When it comes to engine restoration, attention to all the details is necessary when competing in a show. This level of detail work wins gold awards, as with this 1964 Tri-Power engine. The beautiful paint is factory cor¬rect. The fasteners are in perfect condition and have the correct finishes. The engine wiring is correctly shrink-wrapped and held down with the factory-supplied tabs, which are held down with the valve cover bolts. Note the finishes on the bare metal pieces. Brilliant work all around. You can find the hardware and apply the correct paint, but you need to follow this book closely and pay close attention to all the details. (Photo Courtesy Scott Tiemann)

When it comes to engine restoration, attention to all the details is necessary when competing in a show. This level of detail work wins gold awards, as with this 1964 Tri-Power engine. The beautiful paint is factory cor¬rect. The fasteners are in perfect condition and have the correct finishes. The engine wiring is correctly shrink-wrapped and held down with the factory-supplied tabs, which are held down with the valve cover bolts. Note the finishes on the bare metal pieces. Brilliant work all around. You can find the hardware and apply the correct paint, but you need to follow this book closely and pay close attention to all the details. (Photo Courtesy Scott Tiemann)

 

Original Pontiac engine block colors and other engine bay colors are readily available from a number of suppliers. A pro¬fessional paint gun provides the best results because of its superior application, but spray paint in rattle cans also provides impressive results. Pontiac Light Blue Metallic was offered on 1966-1970 Pontiac sixes and V-8s while 1959–1965 Pontiac V-8s are offered in Light Blue. The Light Blue Metallic was offered on so many cars and many businesses offer this color, including Ames, Classic Industries, Krylon-Dupli-color, and PPG. Light Blue is available from Ames, Classic Industries, DuPont, Plasti-Kote, Performance Years, and others. As with any other type of painting, be sure that the block is

Original Pontiac engine block colors and other engine bay colors are readily available from a number of suppliers. A pro¬fessional paint gun provides the best results because of its superior application, but spray paint in rattle cans also provides impressive results. Pontiac Light Blue Metallic was offered on 1966-1970 Pontiac sixes and V-8s while 1959–1965 Pontiac V-8s are offered in Light Blue. The Light Blue Metallic was offered on so many cars and many businesses offer this color, including Ames, Classic Industries, Krylon-Dupli-color, and PPG. Light Blue is available from Ames, Classic Industries, DuPont, Plasti-Kote, Performance Years, and others. As with any other type of painting, be sure that the block is

 

Bill Hirsch Automotive Products offers a wide range of high-quality automotive paints, including a high-temperature, high-gloss engine enamel paint. This paint matches the factory cast-iron GTO exhaust manifold finish so your GTO’s value benefits from this correct finish. If you are using a spray gun and you want the best results possible, a high-temperature, high-gloss paint, such as Bill Hirsch, does a great job. This paint is safe to 700 degrees F, so it holds up bet¬ter than other types. (Photo Courtesy Bill Hirsch Automotive Products)

Bill Hirsch Automotive Products offers a wide range of high-quality automotive paints, including a high-temperature, high-gloss engine enamel paint. This paint matches the factory cast-iron GTO exhaust manifold finish so your GTO’s value benefits from this correct finish. If you are using a spray gun and you want the best results possible, a high-temperature, high-gloss paint, such as Bill Hirsch, does a great job. This paint is safe to 700 degrees F, so it holds up bet¬ter than other types. (Photo Courtesy Bill Hirsch Automotive Products)

 

Bill Hirsch Automotive Products offers a wide range of high-quality automotive paints, including a high-temperature, high-gloss engine enamel paint. This paint matches the factory cast-iron GTO exhaust manifold finish so your GTO’s value benefits from this correct finish. If you are using a spray gun and you want the best results possible, a high-temperature, high-gloss paint, such as Bill Hirsch, does a great job. This paint is safe to 700 degrees F, so it holds up bet¬ter than other types. (Photo Courtesy Bill Hirsch Automotive Products)

Replicating as-cast finishes in paint helps ward off rust and retains a fresh appearance. These Eastwood paints are specially formulated for that purpose. Eastwood offers paint that mim¬ics the color and gloss level of cast iron, cast aluminum, and even cadmium plating. (Photo Courtesy Eastwood)

 

This Butler Performance stroker kit features forged rods, pistons, and a crank¬shaft. Best of all, it can be slipped into a regular 389 or 400 block and provides a huge increase in displacement and torque, while retaining a bone-stock look. (Photo Courtesy Butler Performance)

This Butler Performance stroker kit features forged rods, pistons, and a crank¬shaft. Best of all, it can be slipped into a regular 389 or 400 block and provides a huge increase in displacement and torque, while retaining a bone-stock look. (Photo Courtesy Butler Performance)

LSB

 

Although it seems like nothing really stops the problem dead in its tracks, many restorers and engine builders have had good luck with priming those areas with several coats of VHT header paint. The rough-cast finish of the exhaust port and the flat finish of the paint work provide a good base for top-coat adherence. If you are using a spray gun, look for a high-temperature version of the cor­rect-year engine paint for your Pon­tiac engine. A product like Bill Hirsch Engine Enamel does a good job.

If you find that your exhaust ports are still starting to discolor after a few weeks of driving, make a template to mask off the surround­ing areas of your engine and touch them up. It generally needs to be done once or twice each season. It is just one of the little idiosyncrasies of owning a Pontiac.

For exhaust manifolds, use East­wood’s Factory Gray Hi-Temp Coat­ing. It does a great job of replicating the color of bare cast iron without the threat of rusting like a bare metal piece inevitably does. Interestingly enough, the manifolds don’t get as hot as the exhaust port, so this paint holds up fine.

Other Eastwood paints do a great job of replicating bare cast finishes. If you want to retain that fresh-cast look on aluminum and other sur­faces, check out its detailing paints.

Fasteners, Wiring and Hoses

Once again, the automotive aftermarket has come to the rescue with many items that have long since been depleted from dealer inventories. Even more importantly, wearable items, such as hoses and belts, should be replaced with newly manufactured items. The reasoning is this: even if you could find one, do you want a 40-year-old radiator hose on your car? Do you want fuel lines not resistant to today’s gasolines, which contain at least 10-percent ethanol? How about old plug wires arcing between each other? No, no, and no.

If you are looking to increase the power of your Pontiac stroker motor and aren’t concerned about looking completely correct under the hood, this Edelbrock Per¬former RPM intake manifold offers a substantial increase in airflow and also shaves more than 40 pounds off the nose of your GTO. This high-performance top end can be painted to give a more factory-stock appearance. (Photo Courtesy Edelbrock)

If you are looking to increase the power of your Pontiac stroker motor and aren’t concerned about looking completely correct under the hood, this Edelbrock Per¬former RPM intake manifold offers a substantial increase in airflow and also shaves more than 40 pounds off the nose of your GTO. This high-performance top end can be painted to give a more factory-stock appearance. (Photo Courtesy Edelbrock)

 

Reproduction Ram Air exhaust manifolds are a great choice for those seeking additional performance but do not want the leaking and ground clear¬ance problems associated with headers. These can be ported or extrude honed for additional flow, though care must be taken to make sure they do not get too thin. (Photo Courtesy Ram Air Restoration Enterprises)

Reproduction Ram Air exhaust manifolds are a great choice for those seeking additional performance but do not want the leaking and ground clear¬ance problems associated with headers. These can be ported or extrude honed for additional flow, though care must be taken to make sure they do not get too thin. (Photo Courtesy Ram Air Restoration Enterprises)

 

Quality control markings, like this one (OK-5), can be replicated using rubber stamps from companies such as Inline Tube. (Photo Courtesy Scott Tiemann)

Quality control markings, like this one (OK-5), can be replicated using rubber stamps from companies such as Inline Tube. (Photo Courtesy Scott Tiemann)

 

Replacement hoses and wiring should always be new for two reasons: old items crack and fail and old items can be harmed by today’s “alcohol-enhanced” fuels. (Photo Courtesy of Ames Performance Engineering)

Replacement hoses and wiring should always be new for two reasons: old items crack and fail and old items can be harmed by today’s “alcohol-enhanced” fuels. (Photo Courtesy of Ames Performance Engineering)

With companies like Ames Per­formance Engineering, Original Parts Group, Year One, and Performance Years taking the time and money to invest in the manufac­ture of quality reproduction hoses, correct clamps, distributor caps, engine wiring harnesses, wire loom separators, plug wires, Ram Air pan gaskets, and other related items, it has become customary in the last decade or so to refrain from seeking out original pieces. Instead, restorers grab the latest GTO restoration cata­logs to see who has what and who has the best deals.

Again, the Pontiac message boards are great places to see what supplier pieces are better than others and which ones come from the same supplier. You’d be surprised by how much of it is the same.

 

Engine Disassembly and Inspection

 

Step-1: Remove Carb and Valve Covers

1You don’t know what lurks inside a Pontiac V-8 until you disassemble it and thor­oughly inspect all of the components. A crucial part of inspection is not only identifying obvious and not-so-obvious damage, but also determin­ing which component problems, parts failures, and assembly issues caused the problems in the first place. If you don’t identify and remedy the core problem that initiated or created the failure in the first place, when you rebuild the engine the core problem will still exist and the engine could likely fail again. There’s nothing more demoral­izing than tearing down the entire long block, performing a diligent rebuild, only for the engine to grenade again. (Photo Courtesy Butler Perfor­mance)

Step-2: Inspect Cylinder Bores and Block

2The cylinder bore wear can be seen from both ends but you can see if there are cracks at the bottom of the bores. Also, keep in mind that the number-4 main cap holds the thrust bearing and this is the journal that takes the most abuse. Pay particular attention to this area and look for visible cracks. There may be some that you cannot see but if they can be seen, you likely have a block that is not usable. If it passes a visual inspection, you may still want to have it Magnafluxed to detect other cracks. (Photo Courtesy Butler Performance.)

Step-3: Inspect Lifter Valley and Block

3Pontiac blocks have an inherent weakness in the lifter bore area. It is largely open and there is not a lot of metal, so if there is excessive spring pressure and/or cam lift, cracks may appear or a lifter bore can break. Extreme high-horsepower cases have seen blocks split down the middle, but it is a rarity with street engines. A worthwhile upgrade for a performance rebuild is an SD Performance Mega Brace, which supports the lifter bores and greatly increases the strength of the block. (Photo Courtesy Butler Performance.)

Step-4: Inspect Cylinder Walls

4With any engine that has seen high-mileage and hard use, the cylinder walls show wear and sometimes scoring. This particular block shows extreme scoring and needs an overbore. Feel for a notch or a ridge around the circumference of the top of the bore. One typically develops after many miles and/ or hard use. If one has developed, the block needs to be over­bored. Any visual damage also requires an overbore.

Use a telescoping micrometer to take precise measurements at the top middle and bottom of the bore. Compare these measure­ments to the stock specs to determine the amount of overbore required.

A .030-inch boring procedure usually cleans up any cylinder wall damage and allows enough material for a future rebuild. Even so, you need to determine the size of overbore before you order pistons, as another pass on the boring bar may result in pistons too small for your build.

Step-5: Measure Engine Block

5This cylinder wall has been deeply scored, which necessitates an engine overbore. Use a telescoping micrometer to measure the bore size at the top, bottom, and middle. If the block wall is too thin and it’s been overbored to .060 inch, have it sleeved or replace the block. You can go with an OEM unit or an aftermarket block that supports much more horsepower than stock. But of course, then the engine is not factory correct and the engine package is worth far less.

Step-6: Inspect Engine Internals

6This engine has suffered severe engine damage. The entire main bearing is nearly worn away, and when it wore it sent metal throughout the entire engine that damaged the bearings, the connecting rods, crank­shaft, and cylinder walls. Main bearings should never look like this, and if they do, expect to see damage throughout the entire engine.

 

Step-7: Inspect Crankshaft Journal

7Crankshaft journal damage is ugly, and this crank­shaft may need to be replaced. Use a caliper micrometer to measure the journals near the fillets and also in the center of the journals to determine any variance or unusual wear pattern. The crankshaft main journal spec for a Pontiac V-8 is 3.00 or 3.25 inches. (Photo Courtesy Butler Performance)

 

Step-8: Inspect Crankshaft Journal

8

Another view of this deeply scored crankshaft journal. Pontiac V-8 rod journal diameters measure 2.249 to 2.500 inches. These oil feed holes supply lubri¬cation to the main bearings.

 
 

Step-9: Inspect Crankshaft Journal

9Metal from the main cap bearings have embedded in the crankshaft journals. Note that the oil holes in the crankshaft journal have been slightly chamfered. The crankshaft journals have suffered enormous damage and must be turned down. Oversized bearings must be fitted to the crankshaft. Crankshaft runout must be measured as well.

 

Step-10: Inspect Connecting Rod Bearing Caps

10The connecting rod bearing caps are severly worn and remind me of the damage caused from debris that’s sucked into the engine. On the other hand, if the connecting rod bearings are copper in color, that means the engine has probably suffered detonation. (Photo Courtesy Butler Performance)

 

Step-11: Inspect Connecting Rods

11The connecting rods have suffered significant wear during their service inside the engine. The original I-beam rod can now be stress relieved and shot peened, but the surface area has suffered extreme wear and must be overbored. In addition, it requires larger rod bearings to accommodate the increased size. Any time you’re rebuilding an engine you should invest the money and replace the stock rods with stronger forged rods. Rods are under enormous stress and heat cycling changes the metallurgy of the rods over time and weakens them. Most stock cast rods in a stock engine can last well over 100,000 miles, but if you’re rebuild­ing an engine, buy new rods according to your performance goals. (Photo Courtesy Butler Performance)

Step-12: Inspect Main Bearing Caps

12The damage to this main bearing cap is plainly evident and deep scratches indicate that debris or other material circulated through the engine and dam­aged the bearings. (Photo Courtesy Butler Performance)

 
 

Step-13: Inspect Main Bearing Caps

13After removing the main bearing caps, inspect the main bearings. As you can see, these bearings are heavily worn and must be replaced. The heavy grooves indicate that contamination at some point crept into the engine and caused this damage, or at some point there was oil starvation and the friction between the crank and the main bearings wore them out. Whenever you rebuild an engine, install new main bearing caps. (Photo Courtesy Butler Performance)

Step-14: Inspect Bearings

14The cam bearings on this engine also need to be replaced. This operation should be performed by your machine shop, as it will ensure they are square to the block, which is essential to proper camshaft break-in and longevity. (Photo Courtesy Butler Performance)


 
 

Engine Assembly

 

Step-1: Install Main Bearing Caps

1The Pontiac V-8 main bearing caps and connect­ing rods have been installed. This particular block has two-bolt main bearing caps. In three steps, torque the rear main bearing cap using a 15/16-inch socket. For the rear main bearing cap, torque to 40, 80, and then 120 ft-lbs. The rest of the main bearing caps are torqued to 80 ft-lbs in three steps. Once the main bearing caps have been torqued in place, verify that the crankshaft turns freely and there are no impedi­ments. Turn the crankshaft over and feel for any restric­tions. (Photo Courtesy Butler Performance)

 
 

Step-2: Select Rods and Pistons

2When rebuilding a Pontiac V-8, you can opt for the OEM cast pistons and I-beam rods. However, if you’re horsepower target is significantly above stock, you need some high-performance engine internals, and those include forged H-beam rods and forged pistons. This piston-and-rod assem­bly can cope with up to 700 hp.

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Step-3: Inspect Piston

3In preparation for installing the pistons in the block, you need to complete the piston and rod assemblies. Use a piston ring tool to install the three piston rings. Once the rings are installed, install the wrist pin and connecting rod to the piston. The pressed pin is stock type and the floating wrist pin uses a bronze bushing. Be sure that correct clearance is achieved for the particular type of wrist pin, which means carefully measuring the small end of the rod and the pin itself. The pistons and connecting rods must match the requirements of the particular rebuild. Therefore, the rod length and big-end diameter must match the crank journal measurements. The piston must have the correct clearance to the valves. If the piston comes in contact with the valves, catastrophic engine damage will occur.

Step-4: Torque Connecting Rod Bolts

4The piston-and-rod assemblies have been installed through the bores. And the connecting rod caps and nuts have been installed, so at this stage, it’s time to correctly torque the rod nuts to the appropriate torque spec. First, check with the rod manufacturer for the correct torque spec. The OEM and ARP fastener torque specs are often different and incompatible, so if you use the wrong torque spec, you may strip the fasteners. The factory torque spec for connect­ing rods is 43 ft-lbs. Use a 9/16-inch socket on a click-type torque wrench and torque the nuts to 15, 30, and finally 43 ft-lbs for the OEM nuts.

Step-5: Measure Piston-to-Valve Clearance

5Once the pistons have been installed, you need to measure piston-to-valve clearance. Install the dial indicator and then rotate piston number-1 to TDC. At TDC, the dial indicator should measure no less than .080 inch for intake valves and .100 inch for exhausts. If the measurement is less than this, the crowns of the pistons may come in contact with the valves, and catastrophic engine failure can occur. Another way to take this measurement is by using modeling clay. Put the clay between the piston and the valve, rotate the engine, and then measure the depressed clay. Typi­cally, using a stock-lift cam does not have an issue. If you are using an aftermarket cam profile, check with the manufacturer for recommenda­tions on this critical clearance mea­surement. (Photo Courtesy Thomas A. DeMauro)

Step-6: Install Dipstick Tube and Oil Pickup

6Once the connecting rods have been properly installed, install the lower dipstick tube. Insert the tube into the intermediate tube in the block. It is held in place with the windage tray. After coating the threads with thread-lock adhesive, use a 1/2-inch socket to torque the windage tray bolts to 15 ft-lbs. At this stage you also need to install the oil pump. Place the pickup tube in a freezer overnight so it contracts. When it is cold enough, it slips inside the oil pump body. Use a 3/4-inch open-end wrench and a hammer to insert the tube into the oil pump body. Then slot the oil pump shaft into the oil pump drive in the block. Two bolts fasten the oil pump to the block; torque them to 30 ft-lbs. (Photo Courtesy Thomas A. DeMauro)

Step-7: Prep Heads for Installation

7Prepare the Edelbrock D port head for installation. (Photo Courtesy Thomas A. DeMauro)

 
 

Step-8: Torque Head Bolts

8Smoothly and evenly apply force when torquing down the head. A jerking motion can cause inaccurate readings. The torque wrench will click when the proper amount of force is applied. (Photo Courtesy Rocky Rotella)

 
 

Step-9: Install Manifold and Carb

9Once the heads and valvetrain have been installed, you can install the valley pan and intake manifold. Place the intake manifold gasket over the studs and into position. Place a pinch of gasket sealer on each side to hold it in the desired centered position, so it doesn’t move around. Lower the manifold into its correct position. By hand, thread all the manifold bolts until they are properly seated. Install the timing covers next and torque these bolts to 15 ft-lbs. Using an alternating torque pattern, tighten the manifold bolts to 40 ft-lbs. Then, place the carb gasket on the intake manifold. Slide the carb over the four manifold studs, and then torque the carb mount­ing nuts to 5 ft-lbs. (Photo Courtesy Thomas A. DeMauro)

Step-10: Install Distributor

10Unless you’re restoring a 100-point concours car, you should install an HEI or similar distributor. A modern electronic distributor gives you far stronger and more consistent spark, and it doesn’t wear over time and require adjustment like a points-type distributor. The distributor gear needs to be compatible with the cam, and many distributors require a different gear for a roller camshaft. On the compression stroke, place the number-1 piston at TDC. Align the distributor’s rotor tip with the cylinder number-1 terminal. Make sure the distributor is sitting flush against the block and rotate the distributor to the right for the first time to run the engine. Then fasten the hold-down clamp with the appropriate socket. With a counterclockwise pattern, install the cap and route the plug wires to the correct cylinders in a 1-8-4-3-6-5-7-2 arrangement. (Photo Courtesy Thomas A. DeMauro)

Step-11: Inspect Valvetrain

11As you peer into the lifter valley, you can see the newly installed lifters and pushrods riding on the cam. Be sure to apply a good coat of the recommended break-in lube on the camshaft and lifters because you do not want the cam to prematurely wear on first start up of the engine. Submerge the lifters and rocker arms in 30W engine oil so these parts are thoroughly lubricated and prepared for operation. Flat-tappet cams require coating the face of the lifters and the lifter faces are definitely coated in this photo. The lifters should easily slide and move up and down in the bores. If there is any restriction or slop in the lifter bores, the lifter bores must be resurfaced. In addition, the pushrods should simply slide down through the heads and rest squarely on the lifters. There should be no impediments or restric­tions, and the pushrods should match up with the stock stamped rocker arms. (Photo Courtesy Butler Performance)

Step-12: Perform Final Procedures

12The engine is near final assembly. A number of proce­dures must be done before it is completed, such as installing the carb linkages, belts, valve covers, and fuel pump. A factory-correct restoration includes using the correct factory paint, and this V-8 is adorned with Light Blue Metallic. No matter what engine paint is required for your particular Pontiac V-8, be sure that it’s an accurate representation of the original paint. Do your research, look at message boards, talk to profes­sional restorers, and best of all get recommendations from judges and club members so you use the best quality and most accurate paint available. If you get the paint wrong and you plan on entering the car in car shows, it will be judged harshly for this particular drawback. (Photo Courtesy Butler Performance)

 

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