The key to maximizing the performance of any combination is proper component selection. By expanding on the approach that Pontiac took when assembling combinations for its production vehicles, selecting components that compliment the operating characteristics of one another for a particular application, you typically produce a powerful engine that operates efficiently and reliably over a long period of time.
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There are a great number of machine shops, engine assemblers, and engine builders located throughout the country, and most are qualified to assist you in your quest for assembling a combination for your Pontiac V-8 that meets your performance expectations. Contact information for several companies that are intimately familiar with Pontiacs can be found in the Source Guide.
Here I provide you with an assortment of proven engine combinations from professional engine builders that use commonly available Pontiac engines as the basis. While any of those companies listed in the Source Guide should be capable of providing you with quality service and a reliable combination, space constraints prohibit listing every complete engine combination from each. In fairness to all, sources are limited to those companies that build Pontiac engines exclusively. That doesn’t remotely suggest, however, that others aren’t as knowledgeable or talented.
A select number of Pontiacspecific engine builders were each assigned a “stock” and “modified” engine package, using an engine of specific displacement and the intended parameters. The instruction stated that the package must operate reliably and perform within a reasonable range of the estimated horsepower and torque values provided.
The intent of the “stock” combination was to end up with an engine that performs well while maintaining excellent street manners and a completely stock appearance. The builders were told that it must include cast-iron cylinder heads with mild modifications possible, a stockstroke crankshaft, a hydraulic flattappet camshaft, original intake and exhaust manifolds, and an original carburetor.
The goal of the “modified” combination was to produce a highperformance engine that maintains a stock appearance and has good street manners. The use of certain aftermarket components was permissible, and these included certain aluminum cylinder heads, any aftermarket dual-plane intake manifold, and a roller camshaft, but it did require an original carburetor and cast-iron exhaust manifolds.
The combinations on the following pages can be considered guidelines to arrive at the supplied horsepower and torque estimations. While any number of components could certainly be swapped for a like item, longevity, performance, or street manners could suffer. I suggest that effects of any variance outside the stated combination be verified with your builder.
Dave Bisschop: SD Performance
Dave Bisschop is well known for taking a moderate approach toward building strong performance engines. In fact, he has been building and racing Pontiacs for a number of years, and has spent a great deal of time finding ways to extract even more performance from stock Pontiac components. Some of the quickest stock-appearing Pontiacs in the country feature cylinder heads that have been ported by his company in Chilliwack, British Columbia. Dave is considered to be among the best Pontiac builders.
Stock 389 Tri-Power
Short Block
Block Casting: Original 389 block or equivalent 389 or 400 replacement
Preparation: Clean and magnetic particle inspect for cracks Crankshaft: Correct crankshaft for block or equivalent replacement
Preparation: Clean and magnetic particle inspect for cracks; grind to next undersize as needed and fully polish
Bore/Stroke: 4.06- to 4.12-inch bore/3.75-inch stroke Displacement: 389 to 411 ci
Deck Height: 10.22 inches
Pistons: Forged-aluminum flat tops or dished to achieve 9.5:1 (compression depends on type of fuel being used)
Piston Rings: File-fit plasma-moly rings with .018- to .020- inch gap or drop-in moly rings
Piston-to-Wall Clearance: Per piston manufacturer’s specifications
Connecting Rods: Tomahawk 5140 connecting rods
Connecting Rod Side Clearance: Minimum of .012 inch
Main Bearings: Clevite or Federal-Mogul (standard bearings) with .0020 to .0025 inch of clearance
Rod Bearings: Clevite or Federal-Mogul (standard bearings) with .0020 to .0030 inch of clearance
Thrust Clearance: .0040 to .0090 inch
Windage Tray: Tomahawk OE replacement
Oil Pump: Melling M54DS 60 psi; disassemble, clean, check for approximately .0030 inch of clearance between gears and bottom plate
Oil Pan: Original or OE replacement with baffle if replacement is required
Camshaft
Camshaft: Elgin Hydraulic flat-tappet
Camshaft Bearings: Dura-Bond
Bearing Clearance: minimum of .0012 inch (cam should turn by grabbing the snout with hand and turn)
Duration at .050 inch: 214/224
Lobe Separation: 112 degrees
Valve Lift at 1.5:1: .444/.466 inch
Intake Centerline Installed at: 107 to 108 degrees
Pushrods: Original or OE replacement
Rocker Studs: Original or ARP replacement
Rocker Arms: Original stamped-steel 1.5:1 or PRW full roller in 1.52:1 if budget allows
Timing Set: JP billet 9-keyway double roller
Cylinder Heads
Castings: Correct castings for the application (716, 77, 093) or equivalent.
Preparation: Clean and magnetic particle inspect for cracks
Combustion Chamber Volume: Verify original chamber volume; pistons should be matched to chamber size to achieve 9.25 to 9.5:1 compression
Compression Ratio: 9.25 to 9.5:1
Suggested Airflow at 28 inches: 200 to 230 cfm at .550- inch lift
Valves: Ferrea or SI stainless steel
Valve Diameters: 1.94/1.65 inches with 389 heads or 2.11/1.77 inches with later heads
Valve and Seat Preparation: Multi-angle valve job, install hardened exhaust seats in 389 heads; non-hardened exhaust seat heads can be used if enthusiast plans to drive a lot
Valvesprings: Dual springs with 100 to 115 pounds of seat pressure and a maximum of 280 pounds of open pressure
Valve Locks and Retainers: 7-degree Manley or Comp Cams
Induction
Intake Manifold: Original Tri-Power for the application or factory cast-iron Quadrajet from 1967 and later
Preparation: Clean, gasket match, and remove any large casting flash in the runners
Carburetor: Original or equivalent replacements calibrated accordingly
Ignition
Distributor: Original or equivalent replacement
Range of Initial Timing: 10 to 15 degrees
Range of Total Timing: 34 to 38 degrees
Suggested Fuel Octane: 92
Exhaust
Exhaust Manifold: Originals or Ram Air Restorations reproduction performance manifolds Exhaust Tube Diameter: 2.25 to 2.5 inches
Muffler: Dynomax or similar large body muffler to deliver good flow and a healthy sound without too much incar noise
Exhaust Crossover: An X-type crossover if any is considered Or Complete Exhaust Kit: Ram Air Restoration kits
Gearing
Auto Trans Converter Stall Speed: 2,200 to 2,500 rpm
Suggested Rear Axle Ratio: 3.08 to 3.55:1, depending upon the type of driving planned, or 3.90:1 for drag strip performance
Projected Output
Estimated Horsepower: 350 to 390
Estimated Torque: 425 to 450 ft-lbs Modified 455 4-Barrel
Modified 455 4-Barrel
Short Block
Block Casting: Any 455
Preparation: Clean, steel-shot blast, and magnetic particle inspect for cracks; remove casting flash from the lifter valley; tap front oil galley plugs for screw-in studs
Crankshaft: Cast-steel from Eagle or 4340 forged-steel from Scat or SGI in 4.25-inch stroke
Preparation: Balance and polish
Bore/Stroke: 4.155- to 4.195-inch bore/4.25-inch stroke
Displacement: 461 to 470 ci
Deck Height: 10.22 inches Pistons: Ross forged-aluminum
Piston Rings: Plasma-Moly with .018- to .020-inch gap
Piston-to-Wall Clearance: .005 inch
Connecting Rods: Eagle 6.8-inch length; check and fit pin bushings for correct pin clearance
Connecting Rod Side Clearance: .028 inch or greater is typical
Main Bearings: Clevite77 or Federal-Mogul (standard bearings) with .0020 to .0025 inch of clearance
Rod Bearings: Federal-Mogul 8-7200CH with .0020 to .0030 inch of clearance
Thrust Clearance: .004 to .009 inch
Windage Tray: Tomahawk OE Replacement
Oil Pump: Melling M54DS 60-psi; disassemble, clean, check for approximately .003 inch of clearance between gears and bottom plate; shim relief spring .060 inch for added pressure
Oil Pan: Baffled original or Canton Road Race 15-450 or 15-452
Camshaft
Camshaft: Comp Cams Custom hydraulic roller, “Stump Puller”
Camshaft Bearings: Dura-Bond
Bearing Clearance: Minimum of .0012 inch (cam should turn by grabbing the snout with hand and turn)
Duration at .050 inch: 230/236
Lobe Separation: 112 degrees Valve Lift at 1.5:1: .565/.570 inch
Intake Centerline Installed at: 107 to 109 degrees
Pushrods (type): Smith Brothers .083-inch wall replacements
Rocker Studs: 7/16-inch ARP
Rocker Arms (type and ratio): PRW full roller rocker (aluminum or stainless steel) in 1.52:1
Timing Set: JP billet 9-keyway double roller
Cylinder Heads
Castings: Most 1967-and-later castings, other than those used on low-compression 455s that accept 2.11/1.77- inch valves.
Preparation: SD Performance 250-cfm CNC-Ported Head package
Combustion Chamber Volume: Verify original chamber volume; pistons should be matched to chamber size to achieve 9.25 to 9.5:1 compression
Compression Ratio: 9.25 to 9.5:1
Suggested Airflow at 28 inches: At least 250 cfm at .550- inch lift
Valves (type): Ferrea, SI, or Manley stainless-steel
Valve Diameters: 2.11/1.77 inches
Valve and Seat Preparation: Four-angle seat cut with 45- degree seats and 30-degree back cut on valves at least .060-inch wide
Valvesprings: Comp 995 dual springs installed at 1.65 inches with 130 to 140 pounds of seat pressure and 340 to 350 pounds of open pressure
Valve Locks and Retainers: 10-degree Manley or Comp Cams, chrome-moly.
Induction
Intake Manifold: Factory cast-iron Quadrajet from 1967 and later
Preparation: SD Performance CNC machining to plenum and port matching
Carburetor: 850+ cfm custom Quadrjaet from Cliff’s Q-jet
Ignition
Distributor: New replacement HEI
Range of Initial Timing: 10 to 15 degrees
Range of Total Timing: 33 to 36 degrees
Suggested Fuel Octane: 91 to 93
Exhaust
Exhaust Manifold (type): Ram Air Restorations with 2.45- inch outlet
Exhaust Tube Diameter: 2.5 inches
Muffler (type): Dynomax Exhaust Crossover: X-type crossover
Or Complete Exhaust Kit: Ram Air Restorations or Pypes
Gearing
Auto Trans Converter Stall Speed: 2,500 to 3,000 rpm
Suggested Rear Axle Ratio: 3.23 to 3.55:1
Projected Output
Estimated Horsepower: 445 to 465
Estimated Torque: 525 to 550 ft-lbs
Ken Brewer: Pacific Performance Racing
Ken Brewer began street racing Pontiacs on the West Coast and quickly gained a name by consistently beating the competition. At the urging of Ken Crocie and Pete McCarthy, he started building engines for friends and decided to open Pacific Performance Racing in San Pedro, California, in 1994. Specializing in Pontiacs of all sizes, Brewer caters to hobbyists who are beginning with engines that generally displace between 326 and 400 ci. His 383 engine package, which is built around a 350 block, has been featured in several national publications, and his popular “Tomahawk” product line provides hobbyists with quality products at an affordable price.
Stock 350 4-Barrel with Small-Valve Heads
Short Block
Block Casting: Original 350 or equivalent replacement
Preparation: Thermal clean and magnetic particle inspect for cracks; align hone and add 2-bolt studs from ARP; bore and hone with torque plate; surface for zero deck
Crankshaft: Original Pontiac crankshaft
Preparation: Grind journals to next possible undersize, micro polish, and balance for pistons and connecting rods
Bore/Stroke: 3.905 x 3.75 inches
Displacement: 360 ci Deck Height: 10.22 inches Pistons: PPR/Probe
Industries 350 forged pistons (2618 material) with .980-inch pin
Piston Rings: Plasma-moly gapped at .018-inch top, .021- inch second, and a minimum of .015 inch at bottom
Piston to Wall Clearance: .004 inch
Connecting Rods: Tomahawk 5140-forged 6.625-inch length
Connecting Rod Side Clearance: .018 to .022 inch
Main Bearings: King MB551AM series (Alecular material) with .0024-inch clearance
Rod Bearings: King CR-815CP with .002- to .0022-inch clearance
Thrust Clearance: .006 inch
Windage Tray: Tomahawk replacement
Oil Pump: Melling 10540; disassemble, inspect, clean, and lube
Oil Pan: Stock Baffled
Camshaft
Camshaft: Tomahawk TC-03-HF hydraulic flat-tappet
Camshaft Bearings: Dura-Bond P-4
Bearing Clearance: .002 inch
Duration at .050 inch: 214/221
Lobe Separation: 112 degrees
Valve Lift at 1.5:1: .450/.455 inch
Intake Centerline Installed at: 108 degrees
Pushrods (type): Pioneer PR-380-16
Rocker Studs: Original or PRW PQ Series 7/16
Rocker Arms (type and ratio): PRW stamped-steel roller-tip rockers in 1.52:1
Timing Set: 78512W SA Gear
Cylinder Heads
Castings: 1968 number-16 or equivalent
Preparation: Clean, magnetic particle inspect for cracks, install bronze guide liners, and surface
Combustion Chamber Volume: 75 cc
Compression Ratio: 9.3:1
Suggested Airflow at 28 inches: 200 to 220 cfm
Valves: Stainless steel
Valve Diameters: 2.08/1.66 inches
Valve and Seat Preparation: Five-angle valve job
Valvesprings: Crower 68405 installed at 1.7 inches with 110 pounds of seat pressure and 280 to 290 pounds of open pressure
Valve Locks and Retainers: 7-degree valve locks
Induction
Intake Manifold: Stock cast iron or Edelbrock
Performer Preparation: None
Carburetor: Quadrajet or Holley 670 Street Avenger
Ignition
Distributor: Tomahawk HEI
Range of Initial Timing: 14 to 16 degrees
Range of Total Timing: 34 to 37 degrees
Suggested Fuel Octane: 91
Exhaust Exhaust Manifold: Stock Exhaust Tube Diameter: 2.25 to 2.5 inches Muffler: Flowmaster Delta Flow Exhaust Crossover: Optional Gearing Auto Trans Converter Stall Speed: Stock Suggested Rear Axle Ratio: 3.08 to 3.42:1 Projected Output Estimated Horsepower: 340 to 355 Estimated Torque: 425 ft-lbs
Modified 350 4-Barrel
Short Block
Block Casting: Any 350 Pontiac block
Preparation: Thermal clean and magnetic particle inspect for cracks; align hone and add 2-bolt studs from ARP, bore and hone with torque plate, and surface for zero deck
Crankshaft: Tomahawk nodular-iron with 4-inch stroke and 2.2-inch rod journals
Preparation: Balance for pistons and connecting rods
Bore/Stroke: 3.905 x 4.00 inches
Displacement: 383 ci
Deck Height: 10.22 inches
Pistons: Probe Industries 383 forged pistons (2618 Material) with .990-inch pin
Piston Rings: Plasma-moly gapped at .018-inch top, .021- inch second, and a minimum of .015 inch at bottom
Piston-to-Wall Clearance: .004-inc
Connecting Rods: Tomahawk Ultra Light 4340-forged 6.8 inches; small end honed to piston pin
Connecting Rod Side Clearance: .018 to .022 inch
Main Bearings: King MB551AM series (Alecular material) with .0024-inch clearance
Rod Bearings: King CR-815CP with .0022-inch clearance
Thrust Clearance: .006 inch
Windage Tray: Tomahawk replacement
Oil Pump: Melling 10540- disassemble, inspect, clean, and lube
Oil Pan: Stock Baffled
Camshaft
Camshaft: Tomahawk TC-03-HR Hydraulic Roller
Camshaft Bearings: Dura-Bond P-4
Bearing Clearance: .002 inch
Duration at .050 inch: 236/244
Lobe Separation: 112 degrees
Valve Lift at 1.5:1: .558/.558 inch
Intake Centerline Installed at: 108 degrees
Pushrods (type): Crower 8.850 inches
Rocker Studs: PRW PQ Series 7/16
Rocker Arms (type and ratio): PRW stainless steel roller rocker arms in 1.52:1
Timing Set: 78512W SA Gear
Cylinder Heads
Castings: Aluminum KRE D-ports
Preparation: CNC ported by SD Performance
Combustion Chamber Volume: 65 cc
Compression Ratio: 10.9:1
Suggested Airflow at 28 inches: 290 cfm
Valves (type): Stainless
Steel Valve Diameters: 2.11/1.77 inches
Valve and Seat Preparation: Multiple angles
Valvesprings: Crane 99893 dual springs with an install height of 1.8 inches and 140 to 150 pounds of seat pressure and 370 to 380 pounds of open pressure
Valve Locks and Retainers: 10-degree Comp Cams locks and Manley retainers Induction
Intake Manifold: Crosswind dual-plane (if clearance) or Tomahawk intake
Preparation: Port matched
Carburetor: Quadrajet or Holley 760 Street Avenger
Ignition Distributor: Tomahawk HEI
Range of Initial Timing: 12 to 14 degrees
Range of Total Timing: 32 to 35 degrees
Suggested Fuel Octane: 91
Exhaust
Exhaust Manifold: Ram Air Manifolds
Exhaust Tube Diameter: 2.5 inches
Muffler: Flowmaster Delta Flow
Exhaust Crossover: X-type
Gearing
Auto Trans Converter Stall Speed: 2,600 rpm
Suggested Rear Axle Ratio: 3.55 to 3.90:1
Projected Output
Estimated Horsepower: 500
Estimated Torque: 480 ft-lbs
David Butler: Butler Performance
Butler Performance in Leoma, Tennessee, has been building fast Pontiacs for a number of years. Sons David and Rodney have picked up where their father, Jim, left off. David Butler is among the most knowledgeable Pontiac builders and his approach toward any type of Pontiac performance can be backed up with successful results. With the ability to produce a stout performance engine with a stock appearance, or thousands of horsepower from a boosted application, Butler Performance can assist you with all your Pontiac needs.
Stock 1965-1966 421 Tri-Power
Short Block
Block Casting: Any original 421 block
Preparation: Cleaned and magnetic particle inspection, sonic test, de-burr excess flashing, bore and hone with torque plate, line hone with ARP main studs, square deck, install and fit cam bearings and brass freeze plugs
Crankshaft: Stock 4-inch stroke cast crankshaft or aftermarket cast replacement
Preparation: Check for cracks, chamfer oil holes, grind, balance, and micro-polish
Bore/Stroke: 4.12 to 4.154 x 4 inches
Displacement: 428 to 434 ci Deck Height: 10.22 inches
Pistons: Ross custom Butler-spec forged aluminum, dished for pump gas
Piston Rings: Total Seal Classic Race gapped .016 to .018 inch
Piston-to-Wall Clearance: .004 inch
Connecting Rods: 5140 Forged I-Beam with 7/16-inch ARP bolts or H-Beam 4340 forged in stock 6.625-inch length; pin-fit and re-size if needed
Connecting Rod Side Clearance: .020 to .024 inch
Main Bearings: Federal-Mogul
Performance bearings with .0025- to .003-inch clearance
Rod Bearings: Federal-Mogul
Performance bearings with .0022- to .0025-inch clearance
Thrust Clearance: .005 to .009 inch
Windage Tray: Optional
Oil Pump: Melling 60 psi; clean and check all clearances
Oil Pan: Canton baffled stock replacement with 6-quart capacity
Camshaft
Camshaft: Comp Cams Xtreme Energy hydraulic flattappet
Camshaft Bearings: standard Federal-Mogul bearings
Bearing Clearance: Cam should turn by hand
Duration at .050 inch: 224/230
Lobe Separation: 110 or 112 degrees
Valve Lift at 1.5:1: .480/.480 inch
Intake Centerline Installed at: 106 to 108 degrees
Pushrods: 5/16-inch hardened replacements
Rocker Studs: Convert to 7/16-inch screw-in
Rocker Arms: Comp Cams roller-tip in 1.5:1
Timing Set: Butler Performance True Roller timing set with billet gear and 9-keyway crank sprocket
Cylinder Heads
Castings: 1965 numbers-76 or -77 or 1966 numbers-092 or -093
Preparation: Port and polish, and surfaced
Combustion Chamber Volume: 68 to 72 cc
Compression Ratio: 9.25 to 9.5:1
Suggested Airflow at 28 inches: 210 to 220 cfm
Valves: Ferrea stainless steel
Valve Diameters: 1.92/1.66 inches Valve and Seat
Preparation: Three-angle (Butler Spec Serdi cutter)
Valvesprings: Dual springs with 115 pounds of seat pressure and 290 pounds of open pressure
Valve Locks and Retainers: 10-degree, chrome-moly Induction
Intake Manifold: Stock cast iron Tri-Power
Preparation: Port matched
Carburetor: Stock Rochester 2-barrels; rebuilt and jetted Ignition
Distributor type: Stock points-type with Pertronix electronic conversion
Range of Initial Timing: 12 to 14 degrees
Range of Total Timing: 32 to 35 degrees
Suggested Fuel Octane: 91
Exhaust
Exhaust Manifold: Cast-iron Ram Air type
Exhaust Tube Diameter: 2.5 inches
Muffler: Magnaflow
Exhaust Crossover: X-type
Gearing
Auto Trans Converter Stall Speed: 1,800 to 2,200 rpm
Suggested Rear Axle Ratio: 3.23 to 3.55:1
Projected Output Estimated Horsepower: 375 to 390 Estimated Torque: 450 ft-lbs Additional Suggestions or Comments Upgrading to a hydraulic roller camshaft is highly recommended given the changes in today’s readily available oils. Another easy and recommended upgrade is to use a 1969-and-later timing cover and water pump for improved cooling capacity.
Modified 389 Tri-Power
Short Block
Block Casting: Any 389 block; 1965–1966 casting is preferred since starter bolts directly to the block on later model Pontiacs; if earlier 389 block is used with later model transmission, adapter plates that mount the starter are available
Preparation: Cleaned and magnetic particle inspection, sonic test, deburr excess flashing, bore and hone with torque plate, line hone with ARP main studs, square deck, install and fit cam bearings and brass freeze plugs
Crankshaft: Eagle or Scat 4.25-inch stroke cast or forged
Preparation: Measure and polish or turn if necessary to achieve correct dimensions and balance
Bore/Stroke: 4.092 to 4.120 x 4.25 inches
Displacement: 448 to 453 ci Deck Height: 10.22 inches
Pistons: Ross custom Butler-spec forged aluminum
Piston Rings: Total Seal Classic Race file fit; top ring gapped at .018 inch, second ring gapped at .016 inch
Piston-to-Wall Clearance: .004 inch
Connecting Rods: 4340-forged H-Beam in 6.8-inch length; pin-fit and re-size if needed
Connecting Rod Side Clearance: .024 to .028 inch
Main Bearings: Federal-Mogul performance series or Clevite77 gapped at .0028 to .0032 inch
Rod Bearings: Federal-Mogul performance series or Clevite77 gapped at .0025 to .003 inch
Thrust Clearance: .005 to .009 inch
Windage Tray: Aftermarket unit is optional
Oil Pump: Melling modified for Butler Performance; remachined and blueprinted, and .25-inch-thick bottom plate added
Oil Pan: Canton 7-quart
Camshaft
Camshaft: Comp Cams hydraulic roller; custom grind to Butler spec
Camshaft Bearings: Federal-Mogul or Clevite77
Bearing Clearance: Cam should turn by hand Duration at .050 inch: 236/242 or 242/248
Lobe Separation: 110 degrees
Valve Lift at 1.5:1: Approximately .575/.575 inch
Intake Centerline Installed at: 106 to 107 degrees
Pushrods: Butler Performance .116-inch wall chrome-moly
Rocker Studs: ARP 7/16 inch
Rocker Arms: PRW or Comp Cams full roller
Timing Set: Butler Performance True Roller timing set with billet gear and 9-keyway crank sprocket
Cylinder Heads
Castings: Edelbrock Performer D-port
Preparation: Ported, three-angle competition valve job, custom assembled per application
Combustion Chamber Volume: 87 cc
Compression Ratio: 10.5:1
Suggested Airflow at 28 inches: 300 cfm
Valves: Ferrea stainless steel
Valve Diameters: 2.11/1.77 inches
Valve and Seat Preparation: Three-angle valve job
Valvesprings: Comp Cams dual springs with 135 to 140 pounds of seat pressure and 335 to 345 pounds of open pressure
Valve Locks and Retainers: 10-degree, chrome-moly Induction
Intake Manifold: Edelbrock Performer RPM
Preparation: Port matched
Carburetor: Modified 800 Quadrajet
Ignition
Distributor type: MSD Billet
Range of Initial Timing: 14 to 18 degrees
Range of Total Timing: 34 to 37 degrees
Suggested Fuel Octane: 92
Exhaust
Exhaust Manifold: Ram Air Restorations “Super” roundport exhaust manifolds with 3-inch outletExhaust Tube Diameter: 3 inches
Muffler: Magnaflow
Exhaust Crossover: X-type
Gearing
Auto Trans Converter Stall Speed: 2,400 to 2,800 rpm
Suggested Rear Axle Ratio: 3.55:1
Projected Output
Estimated Horsepower: 550
Estimated Torque: 575 to 600 ft-lbs
Additional Suggestions or Comments
A 1969–and-later timing cover and water pump for improved cooling capacity is easy and recommended upgrade.
Many options are available to suit each customer’s application. A 4-inch-stroke crankshaft can be used to produce about 426-ci displacement and a 4.5-inch stroke crankshaft can be used to produce around 480 ci. Billet 4-bolt main caps are recommended when using a 4.5-inch-stroke crankshaft.
Optional equipment includes a Torker 2 or Victor intake manifold, 850- to 950-cfm Holley carburetor, and Doug’s tubular headers. With this combination, 600 or more horsepower is possible with optional equipment. The Barry Grant Six-Shooter is also very popular with 389 and 421 customers who want the Tri-Power look but with modern performance and drivability.
Jeff Kauffman: Kauffman Racing Equipment
Kauffman Racing Equipment (KRE) in Glenmont, Ohio, is among the very best in the today’s Pontiac market. Since introducing its own cast-aluminum D-port cylinder head for Pontiac applications, KRE has gone on to develop various large-bore Pontiac blocks and highperformance cylinder heads. The engine packages designed by Jeff Kauffman provide proven results and rarely fall short of the owner’s expectations.
Stock Low-Compression 400 4-Barrel
Short Block
Block Casting: Any stock 400 block
Preparation: Hot tanked, magnetic particle inspected for cracks, and shot blasted
Crankshaft: Any stock 400 crank
Preparation: Hot tanked, magnetic particle inspected for cracks, and shot blasted
Bore/Stroke: 4.15 x 3.75 inches
Displacement: 406 ci
Deck Height: Stock 10.24 inches
Pistons: TRW or KB Icon forged
Piston Rings: Plasma-moly with .016-inch gap on top and second ring
Piston-to-Wall Clearance: .003 to .0035 inch
Connecting Rods: Pro-Warrior stock replacement 5140- forged 6.625-inch length
Connecting Rod Side Clearance: Minimum of .015 inch
Main Bearings: Federal-Mogul with .002- to .0025-inch clearance
Rod Bearings: Federal-Mogul with .0015- to .002-inch clearance
Thrust Clearance: .004 to .007 inch
Windage Tray: Reuse original if available
Oil Pump: Melling M54DS 60 psi
Oil Pan: New stock replacement
Camshaft
Camshaft: Crower 60918 hydraulic flat-tappet
Camshaft Bearings: Dura-Bond
Bearing Clearance: .003 to .005 inch
Duration at .050 inch: 214/224
Lobe Separation: 112 degrees
Valve Lift at 1.5:1: .444/.467 inch
Intake Centerline Installed at: 108 degrees
Pushrods (type): Stock
Rocker Studs: 7/16-inch ARP screw-in
Rocker Arms (type and ratio): 1.5:1 roller tip
Timing Set: Rollmaster 9-keyway billet
Cylinder Heads
Castings: Common 4X, 5C, or 6X.
Preparation: Hot tanked, magnetic particle inspected for cracks, and shot blasted
Combustion Chamber Volume: 96 to 102 cc
Compression Ratio: 9.0:1
Suggested Airflow at 28 inches: Stock 210 cfm
Valves: Ferrea Stainless Steel
Valve Diameters: 2.11/1.77 inches
Valve and Seat Preparation: Three-angle valve job
Valvesprings: Dual springs with 110 to 115 pounds of seat pressure and 280 to 300 pounds of open pressure
Valve Locks and Retainers: 10-degree, steel
Induction
Intake Manifold: Stock cast-iron 4-barrel
Preparation: Shot blasted
Carburetor: Stock Quadrajet
Ignition
Distributor: MSD 8528
Range of Initial Timing: 8 to 12 degrees
Range of Total Timing: 32 to 36 degrees
Suggested Fuel Octane: 89
Exhaust
Exhaust Manifold: Stock or Ram Air
Exhaust Tube Diameter: 2.5 inches
Muffler: Flowmaster 50 series or equivalent
Exhaust Crossover: Optional Gearing
Auto Trans Converter Stall Speed: Stock 1,800 to 2,000 rpm Suggested
Rear Axle Ratio: Stock 3.08 to 3.23:1
Projected Output
Estimated Horsepower: 300 to 350
Estimated Torque: 375 to 400 ft-lbs
Additional Suggestions or Comments
This is considered a typical stock rebuild in which old or overly stressed components are discarded and replaced with modern-stock replacements. It contains very few performance modifications and is designed for a long life with very little to no maintenance.
Modified 400 4-Barrel
Short Block
Block Casting: Any stock 400 block from 1967 to 1974
Preparation: Hot tanked, magnetic particle inspected for cracks, and shot blasted
Crankshaft: Ohio
Crankshaft forged-steel with 4.5-inch stroke
Preparation: Balanced
Bore/Stroke: 4.155 x 4.5 inches
Displacement: 488 to 494 ci
Deck Height: 10.24 inches
Pistons: KB Icon forged
Piston Rings: Total Seal plasma-moly gapped at .018 inch for top and second
Piston-to-Wall Clearance: .004 to .0055 inch
Connecting Rods: Pro-Warrior forged-steel H-beam in 6.7- inch length
Connecting Rod Side Clearance: a minimum of .015 inch
Main Bearings: Federal-Mogul with .002- to .003-inch clearance
Rod Bearings: Federal-Mogul with .002- to .0025-inch clearance
Thrust Clearance: .004 to .007 inch
Windage Tray: Canton (if used)
Oil Pump: Melling M54DS 60 psi
Oil Pan: Moroso 8-quart
Camshaft
Camshaft: Comp Cams custom hydraulic roller
Camshaft Bearings: Dura-Bond
Bearing Clearance: .003 to .005 inch
Duration at .050 inch: 236/242
Lobe Separation: 112 degrees
Valve Lift at 1.5:1: .600/.600 inch
Intake Centerline Installed at: 108 degrees
Pushrods: Comp Cams
Rocker Studs: 7/16-inch ARP
Rocker Arms: PRW aluminum full roller rockers in 1.65:1
Timing Set: Rollmaster 9-keyway billet
Cylinder Heads
Castings: KRE Aluminum D-ports
Preparation: CNC porting
Combustion Chamber Volume: 85 cc
Compression Ratio: 10.5 to 11.0:1
Suggested Airflow at 28 inches: 310 cfm
Valves: Ferrea stainless steel Valve Diameters: 2.11/1.66 inches Valve and Seat Preparation: Five-angle valve job
Valvesprings: Dual Springs with 135 to 140 pounds of seat pressure and 335 to 370 pounds of open pressure
Valve Locks and Retainers: 10-degree, steel
Induction
Intake Manifold: Edelbrock Performer RPM intake
Preparation: Port matched
Carburetor: Modified 850-cfm Quadrajet
Ignition
Distributor: MSD 8528
Range of Initial Timing: 10 to 14 degrees
Range of Total Timing: 30 to 32 degrees
Suggested Fuel Octane: 89 to 91
Exhaust
Exhaust Manifold: Ram Air Restorations manifolds with 2.5-inch outlets
Exhaust Tube Diameter: 2.5 inches
Muffler: Flowmaster 40 series
Exhaust Crossover: Optional Or, a Complete
Exhaust Kit: Flowmaster with X-type crossover
Gearing
Auto Trans Converter Stall Speed: 2,500 to 2,800 rpm
Suggested Rear Axle Ratio: 3.23 to 3.55:1
Projected Output
Estimated Horsepower: 600 to 615
Estimated Torque: 610 to 630 ft-lbs
Additional Suggestions or Comments
This package is designed to be a sleeper combo and provide great street manners. The engine should idle at around 800 to 850 rpm and offer sufficient vacuum for power brakes. It has an expected power range of 2,500 to 6,000 rpm with a peak power point of 5,600 rpm. That should equate to low maintenance for RPM use and longevity for the street, but should still be very quick on the drag strip. Possible upgrades include installing a KRE Northwind intake manifold and Pro System 1,000-cfm carburetor for an extra 15 to 25 hp. A set of KRE High Port cylinder heads, tubular headers, or a solid roller camshaft increases RPM and power output. Said changes should yield anywhere between 15 and 80 additional horsepower.
Scott Tiemann: Supercar Specialties
Scott Tiemann is generally regarded among the top Pontiac restorers in the business, and he’s been operating his company, Supercar Specialties, in Portland, Michigan, on a full-time basis since 1989. He has being building Pontiac engines longer than he’s been restoring vehicles. His most recent accomplishments as builder and restorer are showcased in two different 1968 Firebird’s he’s completely restored and rebuilt for the popular Pure-Stock class and Factory Appearing Stock Tire (F.A.S.T.) series racing. Both Firebirds are not merely consistent show winners; they are the fastest Pontiac entries in both racing series.
Pure-Stock Series 1968 Pontiac Firebird Ram Air 400
Short Block
Block Casting: Standard 1973 400 block
Preparation: Bore .060 inch with deck plate, short fill with Hard Blok
Crankshaft: Original Pontiac 400 crankshaft
Preparation: Offset grind rod journal .015 inch to produce 3.765-inch stroke and size main journals to normal undersize
Bore/Stroke: 4.185 x 3.765 inches
Displacement: 414.32 ci
Deck Height: 10.22 inches
Pistons: Diamond lightweight custom forged with .927- inch wrist pins
Piston Rings: Low-tension pack with .043-inch top and second and 3.0-mm oil ring thickness with top and second ring gapped at .020 inch
Piston-to-Wall Clearance: .0055 inch
Connecting Rods: Eagle 4340-forged H-beam bushed for full-floating .927-inch pin
Connecting Rod Side Clearance: .025 inch
Main Bearings: Clevite77 with full oil groove and .003- inch clearance
Rod Bearings: Clevite77 with .002- to .003-inch clearance
Thrust Clearance: .005 to .010 inch
Windage Tray: Stock tray with five .5-inch holes added in center
Oil Pump: Melling M54DS stock replacement 60 psi
Oil Pan: Stock pan with several small oil deflectors welded to rear pan wall to keep oil from climbing on acceleration and one front baffle for stopping
Camshaft
Camshaft: Cam Motion hydraulic flat-tappet
Camshaft Bearings: Clevite
Bearing Clearance: .001 to .002 inch
Duration at .050 inch: 232/240
Lobe Separation: 112 degrees
Valve Lift at 1.5:1: .485/.485 inch
Intake Centerline Installed at: 108 degrees
Pushrods: Stock type 5/16-inch diameter with .080-inch wall and length adjusted for proper valve-to-rocker geometry
Rocker Studs: 7/16-inch ARP
Rocker Arms: Stock stamped steel, 1.5:1
Timing Set: Cloyes Double Roller
Cylinder Heads
Castings: 1968-1/2 number-96 Ram Air II round port.
Preparation: Multiple-angle valve job
Combustion Chamber Volume: 65 cc (NHRA blueprint spec)
Compression Ratio: 12.0:1
Suggested Airflow at 28 inches: Stock flow (approximately 214-cfm intake, and exhaust flows 91.12 percent of that value)
Valves: Ferrea stainless steel
Valve Diameters: 2.11/1.77 inches
Valve and Seat Preparation: Multiple angles to optimize low lift flow characteristics
Valvesprings: Dual spring with 130 pounds of seat pressure and 320 pounds of open pressure
Valve Locks and Retainers: Comp Cams lightweight, steel
Induction
Intake Manifold: Stock 1967 to 1970 cast-iron 4-barrel Preparation: Mill mounting flange as required for port alignment
Carburetor: Stock 750-cfm Quadrajet with calibrated idle circuit for clean and crisp idle and throttle response
Ignition
Distributor: Stock Pontiac points-type distributor
Range of Initial Timing: 15 degrees
Range of Total Timing: 36 to 38 degrees
Suggested Fuel Octane: 110
Exhaust Exhaust Manifold: Reproduction round-port long-branch manifolds Exhaust Tube Diameter: 2.5-inch mandrel bent Muffler: Pypes Crossflow Exhaust Crossover: X-type Or Complete Exhaust Kit: Pypes Crossflow system Gearing Auto Trans Converter Stall Speed: 2,500 to 3,000 rpm Suggested Rear Axle Ratio: 4.33:1 Projected Output Measured Horsepower: 470 at 6,000 rpm Measured Torque: 490 ft-lbs at 4,000 rpm Additional Suggestions or Comments This engine is currently the fastest Pontiac combination at the Dan Jensen/Bob Boden Pure Stock Muscle Car drag race. Installed into Rick Mahoney’s 1968 Firebird that weighs 3,450 pounds with driver and has ran a quickest so far of 11.63 at 117.64 mph.
F.A.S.T. Series 1968 Pontiac Firebird Ram Air 400
Short Block
Block Casting: Original 1973 SD-455 block Preparation: De-burr, and bore .060 inch and hone with deck plate
Crankshaft: Forged steel with 4.15-inch stroke
Preparation: Balanced
Bore/Stroke: 4.21 x 4.15 inches
Displacement: 462 ci
Deck Height: 10.22 inches
Pistons: Diamond lightweight custom forged with dome and .927-inch wrist pins
Piston Rings: Low-tension pack with .043-inch top and second and 3.0-mm oil ring thickness with top and second ring gapped at .020 inch
Piston-to-Wall Clearance: .0055 inch
Connecting Rods: Crower forged steel
Connection Rod Side Clearance: .025 inch
Main Bearings: Clevite77 with .003-inch clearance
Rod Bearings: Clevite77 with .003-inch clearance
Thrust Clearance: .007 to .010 inch
Windage Tray: Stock tray with five .500-inch holes added in center
Oil Pump: Melling M54DS stock replacement 60 psi
Oil Pan: Stock pan with several small oil deflectors welded to rear pan wall to keep oil from climbing on acceleration and one front baffle for stopping
Camshaft
Camshaft: Comp Cams solid roller
Camshaft Bearings: 50-mm needle bearings
Bearing Clearance: n/a
Duration at .050 inch: 264/264
Lobe Separation: 112 degrees
Valve Lift at 1.65:1: .700/.700 inch
Intake Centerline Installed at: 110 degrees
Pushrods: 3/8-inch diameter with length adjusted for proper valve-to-rocker geometry
Rocker Studs: T&D shaft system
Rocker Arms: 1.65:1
Cylinder Heads
Castings: 1968-1/2 number-96 Ram Air II round port
Preparation: Porting by SD Performance
Combustion Chamber Volume: 65 cc (NHRA blueprint spec)
Compression Ratio: 14.0:1
Suggested Airflow at 28 inches: 270-cfm intake and 200- cfm exhaust
Valves: Ferrea stainless steel Valve
Diameters: 2.11/1.77 inches
Valve and Seat Preparation: Multiple angles
Valvesprings: Dual spring with 300 pounds of seat pressure and 750 pounds of open pressure
Valve Locks and Retainers: 10-degree, Comp Cams titanium
Induction
Intake Manifold: 1968 Pontiac cast-iron 4-barrel
Preparation: Porting by SD
Performance Carburetor: 800-cfm Quadrajet with calibrated idle circuit for clean and crisp idle and throttle response
Ignition Distributor: MSD electronic
Range of Initial Timing: 15 degrees
Range of Total Timing: 36 to 38 degrees
Suggested Fuel Octane: 112
Exhaust
Exhaust Manifold: Reproduction round-port long-branch manifolds
Exhaust Tube Diameter: 2.5-inch mandrel bent
Muffler: Pypes Crossflow
Exhaust Crossover: X-type Or Complete
Exhaust Kit: Pypes Crossflow system Gearing
Auto Trans Converter Stall Speed: 4,000 rpm
Suggested Rear Axle Ratio: 4.10:1
Projected Output
Measured Horsepower: 650 at 6,400 rpm
Measured Torque: 620 ft-lbs at 4,200 rpm
Additional Suggestions or Comments
This completely stock-looking combination is installed into a 1968
Firebird that races in F.A.S.T. series. It weighs 3,350 pounds with driver and has ran a quickest so far of 10.50 at 132.2 mph.
Written by Rocky Rotella and Posted with Permission of CarTechBooks
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