pontiac performance tips


Staff member

"1. Set Total Timing to 36-40 Degrees BTDC
The lower the compression and shorter the stroke, the more timing is needed.
2. Recurve Distributor to get all of the timing in by 2500 rpm,
unless you have a heavy or poorly geared car, then it should be increased to 3000 rpm or more.
3. Get cold air induction (ram air), or at least open up the air cleaner to expose more filter surface area.
You can also flip the air cleaner lid upside down to increase power. ie (1970 GP)
4. Have a buddy check the throttle opening as you depress accelerator from inside. (engine off)
See if the throttle is opening fully when you mash the go pedal.
5. Open up the exhaust, bigger diameter pipe and ditching restrictive bends helps performance and economy.
Check the 180 degree bends above the axle, you could just eliminate this part of the exhaust and gain flow.
6. Install an exhaust crossover (preferrably X type, but H type is still better than nothing)
Don't forget to have dual exhausts if possible, and mandrel bent tubing.
Try to evacuate the exhaust gasses in a low pressure zone (high speed air), this will increase exhaust scavenging.
7. Headers are a good upgrade, but often leak and warp (my 69 birds turd 3 tube headers).
8. You can install mufflers in parallel to increase exhaust flow.
This means 2 mufflers per pipe, having a splitter before and after the parallel mufflers.
Some mufflers are loud (glass packs), but are still restrictive, find high flow units.
My knock off glass packs got the baffle treatment which hurts flow, if you run them in reverse,
you can smooth out the flow and decrease turbulence caused by the impeding metal pieces.
9. Install a 160 degree thermostat or something lower than you have.
Lower temperature = Denser Air Charge = More Power
10. Charge your battery before each run, this supplies more voltage for firing the plugs.
11. If your air conditioning doesn't work, get rid of the power-robbing belt.
12. Tune your carb,( rods and jets are available for performance), or you can hand modify QJet rods.
QJets are known for being on the lean side, don't "out of the box" the carb,
different applications have varying fuel requirements.
13. Electronic Ignition can gain you consistency and efficiency, power is not guaranteed.
14. Increase plug gap up to .50, if you have Electronic Ignition, very effective with Multiple Spark Setups.
15. If you have resistor type plug wires, they can degrade and add resistance over time, use copper core.
16. Still using points? Use a rotor that has a metal contact which extends out as close to the cap as possible
to the distributor cap contacts. (Jumping a huge gap there will hurt spark potential, losing a couple HP)
17. Most fuel pumps don't accommodate high horsepower setups, upgrade!!
Make sure that your pump can handle your set up, install a pressure gauge nearest to the carb
For a street combo 6 psi at all times is what to shoot for. (note: QJets can't take more than 6 psi)
18. Remove sock filter in gas tank, these can restrict flow and get plugged.
19. Ditch the in carb filter, use a good in line filter only, but don't go without! In carb filters are restrictive.
20. Get an adjustable vacuum modulator to adjust shift points on autos, very useful for throttle response,
and economy. 21. Timing chains stretch over time, get a good double roller or gear setup,
and use a 2-4 degree advancement keyway.(cheap)
22. Use traction bars, or on leaf springs at least clamp the leafs ahead of the axle.
23. Adjustable shocks are important to a good street strip car.
For racing, 90-10 in the front, 50-50 or 60-40 in the rear.
24. Subframe connectors help tighten up the car and improves times. (Don't lose power in chassis bending)
25. Worn out front shocks are good for launching at the strip.
26. Decrease unsprung weight, ie (tires, wheels, rotating masses)
If you have a strong TH350, use it in place of the much heavier TH400, I believe you save 50 unsprung lbs!
27. Decrease total weight, ie (crap in the trunk) 100 pounds = 0.1 seconds on the strip.
28. Use tall skinny front tires in front at the strip, the height gives you more room to take off.
Similar to shallow staging, which allows greater travel of the tire until you finally trip the beams.
29. Nail down a good alignment, otherwise you will go slow and not know why.(check tires for odd wear)
30. Make certain that no brakes are dragging either. (check for hot brakes
31. Synthetic oil decreases friction, which aid durability and performance.
32. Cut the wind, lowering the front of the car can improve aerodynamics, and thus better times.
Remove items such as: mirrors, antennas, wipers, when drag racing.
Don't lower the car too far, unless your car doesn't require much weight transfer.
33. Increase fuel line diameter to at least 3/8.
34. Keep fuel lines cool, insulate them from the exhaust and install a "cool can."
(or make with aluminum line and coffee can, aluminum dissipates heat faster than steel)
35. Move weight from front to rear. ie (battery)
36. Add shims to your distributor to keep timing consistency, by taking up as much slop as you can.
(when distributor is removed, add shims between the gear and the aluminum housing)
This causes irregular timing in Pertronix systems, and misalignment with dist cap.
37. Spoilers not only look cool, but help guide air around the car.
Front spoilers increase aerodynamics, but rear spoilers rarely help a street car on the strip.
38. Remove the front sway bar, this reduces weight and allows the front to rise and transfer weight.
You can also loosen the top nuts on front shocks until you run out of threads,
then put locktight on the threads and double nut. This also lets the front rise immediately
39. A lot of flash can be found in manifolds and headers, take the time to remove the excess metal.
All cast materials can be improved with careful filing of grinding, even a QJet.
40. Choose a cam to work with your setup, not the biggest bumpstick you can find.
Also coordinate cam with a torque converter that stalls in your approximate power band.
Generally if you are running 230 duration at .050 lift, change converters.
The heavier your Poncho, the more drastic stall speed your combination will need.
41. Adjust air valve opening on the QJet to eliminate bog, but open quickly.
Use a screwdriver to hold the adjustment while you loosen the hex underneath,
then finely adjust the position of the screwdriver to change opening tension. (You can feel it)
42. Use different secondary rod hangers and rods to fine tune your carb.
You can drill the hangers to have a two in one, rich and lean hanger.
The shorter the distance from the hole to the perpendicular top part,
the more responsive your secondary fuel metering will be.
43. When drag racing, turn off your ac, heater, and electrical devices.
44. Also close windows, and put up your convertible top.
45. Retain vacuum advance, it improves part throttle acceleration and economy, but does nothing at WOT.
46. Replace points often, they erode and decrease performance almost immediately with a hot coil.
47. Use a "hotter" coil, especially with electronic ignition.
(The hotter the spark, the more explosive the combustion)
48. If performance is paramount, block the exhaust heat crossover in the heads or intake.
Good luck with cool weather drivablility.
49. Use a carb spacer, open type improves high end scavenging and performance.
Some spacers also insulate the carb from heat, which increases density.
50. Ice the intake in between runs, and also douse the radiator.
51. Use plugs with a colder heat range for performance, some plugs are better than others.
52. Cut the ground electrode of a regular type spark plug to explose the Air fuel mixture to the flame kernel.
53. Pop up the back portion of the hood to allow hot pressurized air out of the engine compartment.
54. Some Pontiacs have Tranmission Controlled Spark, which only allows full vacuum advance in high gear.
I believe if you bypass this on 70-71, you get full advance, but 72+ it disables the vacuum advance.
55. Increase the duration of the spark to increase power.
56. Thermal coatings on piston and combustion chamber transfers more heat to power.
57. Perfect the air fuel mixture, theoretical ideal is 14.7:1 A/F. (go by plug color and feel for best power)
58. Give your high compression engine the octane that it needs, 9.5:1 is limit on pump gas. (93 octane)
Don't just go by factor specs for compression, they are often wrong, and sometimes they've been shaved,
You can use a cheap syringe to cc the heads, then add gasket volume, deck height, and piston insets.
59. Modify heads with 3 angle valve job.
The ideal angles are 75, 60, 30, 15 on the intake side, 75, 60, 45, 15 on the exhaust.
30 degree intake valves are better, try and make the total length of the 60 and 40 cuts 1/4 inch combined.
I would try to find some sweet D port head like 13, 16, 62.
I've found that you can get 69-70 GP heads cheap, because people think they aren't hipo.
60. Port your heads, but don't enlarge the ports unless you want to sacrifice low end torque.
Focus on restricted areas and bends, such as the short side radius, and the valve bowls.
61. Open combustion chamber preferred to a closed type.
Heads in the earlier sixties (67 gto) had closed type.
62. Blueprint everything, gasket matching to ports is important.
Align manifolds to the heads by marking centers, (top and sides) don't tighten until they align.
63. Smooth ports at the top of manifolds (intake/heads), and leave roughness at the bottom,
More air flows at the top, so this is the area to focus on for power output.(especially near carb)
Roughness improves economy and atomization when your car is cold.
64. Cam lift doesn't decrease economy and improves power,
Cam duration improves power more but poops on economy.
65. Stock Pontiac rocker arms are rarely 1.5 ratios, they are usually 1.47 or so, and not uniform.
This equates to a lower lift than anticpated.
66. Pontiacs need a higher duration number (by about 10) on the exhaust side.
This is due to the 130 degree bend, and the fact that the exhaust flows more efficiently at high lifts (.400+)
Whereas, the intakes flow great from .100-.300 lift.
67. Shoot for an average intake lift of about .450 to be optimal, higher, and you waste the low lift capabilites of the uniquely designed Pontiac cylinder heads. (Head work should focus on off the seat flow, it's no Chevy)
68. QJet secondary metering hangers can be more reponsive,
by sticking a straightened paperclip under the seat of it.
69. If you want better low end torque, consider recurving your distributor
to minimize the amount of centrifugal advance, low end torque on demand.
70. When searching for low end power, go with long runners, high end = short runners.
Carb spacers can lengthen runners for torque, especially closed ones.
71. Rather than tying off your choke to render it useless,
take the choke plate out, you will gain low end and total power.
(note: you may have to increase primary jet size slightly)"


Staff member
BTW heres an article with a TON of good basic info, its slanted toward PONTIAC, but about 80% or more of the info applies to most american V8 combos
THE FIRST MUSCLE CAR - Pontiac GTO - History 1964 - 1974

Introduction: The Pontiac GTO is considered by many the first true muscle car. Whereas other manufacturers were concentrating on their full size lines, Pontiac saw the potential for dropping a big block engine into an intermediate frame and marketing it at a budget price. Pontiac sneaked past the GM restriction on this combination by making the GTO an option on the Tempest model, creating the hottest performance machine yet. The GTO sold in great numbers and would fuel the competition between GM, Ford, and Chrysler that would keep the muscle car industry thriving for years to come. The GTO would later evolve into the Judge, an extroverted option package of the blotted GTO, and would continue the tradition until the GTO died an embarrassing death in 1974.

1964 Pontiac Tempest GTO

Comments: The year was 1964 and the early stages of the muscle car era were dominated by full size cars. At GM, corporate policy prohibited any intermediate size car from having engines greater than 330 cid. The engineers at Pontiac had a different idea. They boldly made their 389 cid engine an option on the midsize Tempest and called the option package GTO, which copied Ferrari's GTO (Gran Turismo Omologato) model. The GTO package included the 389 V8, quick steering, dual exhaust, and premium tires, a bargain at just $300. The 389 cid engine came with 325bhp with a single 4bbl carb or 348bhp with the optional Tri-Power setup, 3 2bbl carbs. Pontiac hoped to sell 5,000 copies, they ended up selling 32,450. The car that was marketed under a Tiger motif but soon became known as the "Goat" would stand the automobile industry on end and lead to a host of imitators. But no one in the mid-sixties would get it together quite like Pontiac.

Production: Sports Coupe: 7,384 Hardtop Coupe: 18,422 Convertible: 6,644
Engines: 389 V8 325 bhp @ 4800 rpm, 428 lb-ft @ 3200 rpm. 389 V8 (3x2) 348 bhp @ 4900 rpm, 428 lb-ft @ 3200 rpm.
Performance: 389/325: 0-60 in 7.5 sec, 1/4 mile in 15.7 sec @ 92 mph. 389/348: 0-60 in 6.6 sec, 1/4 mile in 14.8 sec @ 95 mph

1965 Pontiac Tempest GTO

Comments: The success of the 1964 model prompted Pontiac to improve the GTO for 1965. Front and rear styling were changed with the GTO getting stacked headlights like Pontiac's full size models. Both versions of the 389 were improved and Pontiac released an over the counter kit that would turn the decorative hood scopes into the first functional ram air setup. These improvements obviously worked as Pontiac sold 75,342 copies, of which 20,547 had the tri-power option.

Production: Sports Coupe: 8,319 Hardtop Coupe: 55,722 Convertible: 11,311
Engines: 389 V8 335 bhp @ 5000 rpm, 431 lb-ft @ 3200 rpm. 389 V8 (3x2) 360 bhp @ 5200 rpm, 431 lb-ft @ 3600 rpm. 389 V8 Ram Air 360bhp @ 5200 rpm, 431 lb-ft @ 3600 rpm
Performance: 389/360 (3x2): 0-60 in 6.1 sec, 1/4 mile in 14.7 sec @ 99mph.

1966 Pontiac GTO

Comments: Pontiac made the GTO its own model for 1966 and was rewarded with sales of 96,946 units, the highest ever for a true muscle car. The GTO was restyled again for 1966 with gorgeous coke-bottle contours with the roof and taillights receiving the most attention. Engine choices remained the same until mid year when GM banned multi-carb setups for all cars except the Chevrolet Corvette, probably in the face increasing emissions standards.

Production: Sports Coupe: 10,363 Hardtop Coupe: 73,785 Convertible: 12,798
Engines: 389 V8 335 bhp @ 5000 rpm, 431 lb-ft @ 3200 rpm. 389 V8 360 bhp @ 5200 rpm, 424 lb-ft @ 3600rpm. 389 V8 Ram Air 360 bhp @ 5200 rpm, 424 lb-ft @ 3600 rpm
Performance: 389/360: 0-60 in 6.5 sec, 1/4 mile in 14.65 sec @ 98mph.

1967 Pontiac GTO

Comments: Undaunted by the death of their tri-power setup, Pontiac unveiled an all new 400 cid enlargement of the 389 cid engine. The rear and grill were restyled again and the new 400 cid engine was available in economy (255bhp), standard (335bhp), High Output (HO) (360bhp) and Ram Air (360bhp) versions. The tiger could still roar.

Production: Sports Coupe: 7,029 Hardtop Coupe: 65,176 Convertible: 9,517
Engines: 400 V8 255 bhp @ 4400rpm, 397 lb-ft @ 4400 bhp. 400 V8 335 bhp @ 5000 rpm, 441 lb-ft @ 3400 rpm. 400 V8 HO 360 bhp @ 5100 rpm, 438 lb-ft @ 3600 rpm. 400 V8 Ram Air 360 bhp @ 5100 rpm, 438 lb-ft @ 3600 rpm.
Performance: 400/255: NA. 400/335: NA. 400/360 HO: 0-60 in 6.6 sec, 1/4 mile in 14.66 sec @ 99mph. 400/360 Ram Air: NA.

1968 Pontiac GTO

Comments: The GTO was drastically restyled for 1968 and gained GM's new split wheelbase A-body. The GTO now sat on a 112 inch wheelbase but was still heavier than the 1967 models. The main news was the new Endura bumper, which was a rubber bumper that gave the car a bumper-less appearance. Furthermore, it was virtually indestructible, as demonstrated in a famous commercial with John DeLorean bashing a GTO's bumper with a sledgehammer, to no effect. A new option was hidden headlights, which were so common that many people thought they were standard. The engine choices remained the same, with the economy and standard 400 cid receiving more horsepower, and all engines were tuned for more torque at lower rpms.

Production: Hardtop Coupe: 77,704 Convertible: 9,980
Engines: 400 V8 265 bhp @ 4600 rpm, 397 lb-ft @ 2400bhp. 400 V8 350 bhp @ 5000 rpm, 445 lb-ft @ 3000 rpm. 400 V8 HO 360 bhp @ 5100 rpm, 445 lb-ft @ 3500 rpm. 400 V8 Ram Air 360 bhp @ 5400 rpm, 445 lb-ft @ 3800 rpm.
Performance: 400/360 HO: 1/4 mile in 14.25 seconds @ 99.0 mph. 400/360 Ram Air: 0-60 in 6.4 sec, 1/4 mile in 14.5 sec @ 98mph.

1969 Pontiac GTO

Comments: The big news for 1969 was the introduction of a new option for the GTO. Rumored to be a sleeper budget model to combat the Plymouth Road Runner, it actually was the opposite. Named after a phrase on the TV show "Laugh In", the Judge was actually a $332 option package that included a new 366bhp Ram Air III 400 cid V8, outrageous body paints, a large rear spoiler, and decals throughout. New to both versions of the GTO was a Ram IV 400 cid V8 seriously underrated at 370bhp, as well as restyled taillights, deletion of the vent windows, and the discontinuation of the HO engine.

Production: Hardtop Coupe: 58,126 Convertible: 7,328 Judge Hardtop Coupe: 6,725 Judge Convertible: 108
Engines: 400 V8 265 bhp @ 4600 rpm, 397 lb-ft @ 2400 bhp. 400 V8 350 bhp @ 5000 rpm, 445 lb-ft @ 3000 rpm. 400 V8 Ram Air III 360 bhp @ 5100 rpm, 445 lb-ft @ 3600 rpm. 400 V8 Ram Air 366 bhp @ 5100 rpm, 445 lb-ft @ 3600 rpm. 400 V8 Ram Air IV 370 bhp @ 5500 rpm, 445 lb-ft @ 3900 rpm.
Performance: 400 RA III/360: 1/4 mile in 13.89 sec. @ 101.4 mph. 400/366 Ram Air: 1/4 mile in 13.70 sec. @ 103.6 mph. 400/370 Ram Air IV: 0-60 in 6.2 sec, 1/4 mile in 14.4 sec @ 98mph.

1970 Pontiac GTO

Comments: The GTO was radically restyled for 1970 and received a new front end with four exposed headlamps wrapped in a Endura bumper, new body creases, and a redesigned rear end. The economy engine was dropped, but a new 455cid engine was added (though it was not available until the end of the 1970 season on the Judge), signaling the end of GM's ban on intermediates with engines greater than 400cid. The GTO had evolved into more of a luxo-cruiser than all-out muscle car, as was the market trend at the time.

A rare option on the 1970 GTO was the Vacuum Operated Exhaust (VOE - Option Code W-73) option. The VOE option was an attempt to simplify the old hot rod trick of opening up the exhaust system for more power. With the VOE option, the driver could pull on a knob under the dash and engine vacuum was routed to a diaphragm on each muffler. The diaphragm opened an internal baffle and gave the exhaust an express route through the muffler. The device reduced backpressure (and thus increased power), but it also significantly increased the noise level caused by the exhaust. This option was available only from early November 1969 through January 1970. That was when Pontiac aired a controversial commercial during the Super Bowl that showed off its VOE option. Top GM executives saw the commercial, and immediately cancelled the option, due to the Federal government's increasing restrictions on emissions and noise levels. Only 233 GTO's were built with the VOE option in that short time, which was priced at just $63.19.

Production: Hardtop Coupe: 32,737 Convertible: 3,615 Judge Hardtop Coupe: 3,629 Judge Convertible: 168
Engines: 400 V8 350 bhp @ 5000 rpm, 445 lb-ft @ 3000 rpm. 400 V8 Ram Air III 366 bhp @ 5100 rpm, 445 lb-ft @ 3600 rpm. 400 V8 Ram Air IV 370 bhp @ 5500 rpm, 445 lb-ft @ 3900 rpm. 455 V8 360 bhp @ 4300 rpm, 500 lb-ft @ 2700 rpm.
Performance: 400/366 Ram Air III: 0-60 in 6.0 sec, 1/4 mile in 14.7 sec @ 98mph.

1971 Pontiac GTO

Comments: In 1971, Pontiac GTO sales which had been declining since the late sixties crashed. Only 374 Judges were produced (including just 17 convertibles), despite having the 455 engine as standard, and this would be its last year. The GTO was also in its last year as its own separate model. Furthermore, GM announced that all engines would have to run on unleaded gas to meet new government regulations and compression ratios and power ratings plummeted. The front end was restyled and Pontiac tried to compensate for the drop in engine power by adjusting the axle ratio and carburetor but to no avail. Performance and sales were on the decline and nothing could hide that.

Production: Hardtop Coupe: 9,497 Convertible: 661 Judge Hardtop Coupe: 357 Judge Convertible: 17
Engines: 400 V8 300 bhp @ 4800 rpm, 400 lb-ft @ 3600 rpm. 455 V8 325 bhp @ 4400 rpm, 455 lb-ft @ 3200 rpm. 455 V8 HO 335 bhp @ 4800 rpm, 480 lb-ft @ 3600 rpm.
Performance: 400/300: 1/4 mile in 14.4 seconds @ 98 mph.

1972 Pontiac GTO

Comments: 1972 saw the GTO revert back to an option on the LeMans and Lemans Sport, costing just $353.88. The Judge was discontinued along with the convertible models (although one GTO convertible is rumored to have been built, along with three (gasp) GTO station wagons). The most noticeable change was in the engine power ratings, which dropped dramaticly. This difference reflected the industry switch from an engine's gross output (power with no accessories) to its SAE Net output (power with accessories attached). This was supposed to be more representative of the actually power delivered to the wheels -- although that didn't really ease the pain for performance seekers. The 400 V8 was now rated at 250 bhp (net) while the 455 was available in either 250 or 300 bhp versions.

Production: Hardtop Coupe: 5,807
Engines: 400 V8 250 bhp @ 4400 rpm, 325 lb-ft @ 3200 rpm. 455 V8 250 bhp @ 3700 rpm, 325 lb-ft @ 2400 rpm. 455 V8 HO 300 bhp @ 4000 rpm, 415 lb-ft @ 3200rpm.
Performance: 455/300: 1/4 mile in 14.6 seconds @ 95.2 mph.

1973 Pontiac GTO

Comments: 1973 saw the end of the once great GTO. New government regulations eliminated the Endura bumper and added a heavy, odd-looking steel one. The hood and tail took on displeasing triangular shapes and this would be the last year the GTO would be based on the LeMans. The 400 V8 was rated at just 230 bhp while the 455 was rated at 250 bhp and was only available with an automatic transmission.

Production: 4,806
Engines: 400 V8 230 bhp @ 4400 rpm, 325 lb-ft @ 3200 rpm. 455 V8 250 bhp @ 3700 rpm, 370 lb-ft @ 2800 rpm.

1974 Pontiac GTO

Comments: For 1974, its last year, the once proud GTO was reduced to an option on the compact Ventura, either as a hatchback or a coupe. Only one engine was offered, a 350 V8 rated at a mere 200 bhp. This marked the first (and only) time the GTO came with any engine smaller than 389 cid, but at least it came standard with the classic "shaker hood" air scoop. Although it died a painful death, the GTO will always be remembered as the Great One that started it all.

Production: 7,058 (2D Coupe: 5,335 2D Hatchback: 1,723)
Engines: 350 V8 200 bhp.
Performance: 0-60 in 7.7 seconds, 1/4 mile in 15.72 seconds @ 88 mph.

I spent decades of time building engines using salvage years as the source for the majority of the components ( I used, and recommended)
I also spent and still spend a great deal of time building engines for myself and others, with huge restrictions on component cost and time.
Brian may think I like to point out high dollar parts....
no I hate having to spend money, on parts especially if theres a perfectly good component you can get at a local salvage yard that will work perfectly well in the application,
that may cost less than 10%-40% of what the aftermarket part may cost.... but I think excellent long term durability is far more important than throwing something together fast and cheaply, that may not last very long If you do the research, and check everything the first time...if you , do things correctly and you don,t need too do it over.
I also built more than a few (several dozen 389,400,421, 428 Pontiac back in the 1960s-1990s, and several more in the last few decades
, or as the old saying goes.. if you can't afford to do it correctly, how are you going to afford to do it over when it self destructs after the original parts selected fail.

yeah it frustrating at times..

here is one area of reality, where the difference lies between the best vs the better ,
and the all too frequent .... guys charging an exorbitant amount of money for inferior work,

you know, exactly what I'm saying if youve ever dealt with skilled machine shops,
and the better mechanics, and all too often, scam machine shops, and fly by night operations, that pop up and go out of business every few years,
and why good machinist and knowledgeable engine builder's ,are so hard to locate, and most have long wait times , too get quality work done..
and why it almost always costs considerably more, and frequently takes longer to have some shops and race teams, work on your car or engine,
its also why many guys get rather pissed off, when they see what it costs for a top quality builder to build any engine.
and without doubt guys in some shops see what the best shops charge and think.. hell, if the best shop in my area, charges that much I should be charging a good deal more,
and I can knock that out for a bit less and in less time and make a killing...... and why finding a good machinist and machine shop is a real challenge in most areas.
I can easily suggest a cam , but its a rather meaningless gesture, and all too frequently a waste of time and effort for both of us.
simply because, without verifying the facts, and this is where Id say the vast majority of internet web sites,
and the recommendations, you see being posted in them, all too often, go wrong far too frequently.
yeah its easy to assume the timings correct the true functional compression, in every cylinder is nearly identical,
(most guys measure, two or three cylinders and without a second thought ignore the rest,
and thus they, blissfully assume all the other cylinders must be the same or so close its a waste of effort,
, most guys fail to put in the effort, too measure the less easily accessed cylinders, thinking
(why bother its a P.I.T.A. and if the first two or three are fine so will the rest of them, )
and that is the attitude that will be used for other factors, yeah, most guys, and every other guy reading similar threads on a vast ocean of similar web sites,
all over the internet, skip over anything that is redundant or takes a bit of extra effort, they simply assume they know things that may or may not be true.
the vast majority of guys , are absolutely convinced, that verifying every measurement and clearance issue in their engine,
in each cylinder is so close that they are effectively duplicate in all areas,
yeah without any doubt... its a waste of time and effort, too do what most guys, will just be convinced is busy work,
yes most tuners and car owners are just like the vast majority and are convinced everything between all the cylinders have not changed are exactly as you and they remember them too be..
especially if they have taken the time and effort too do things correctly several times in the past and found that to be true in the past.
thats the difference between the 5%-10% of guys consistently posting the best and most

consistent time slips and lap times vs the guys that frequently win a few races,
but over a season or two, don,t consistently, year after year build a good reputation, for durability and consistently winning.


http://www.tinindianperformance.com/Tin Indian Performance Pontiac Parts Catalog.htm





http://web.archive.org/web/201006070702 ... ngid1.html




http://www.angelfire.com/fl4/pontiacdud ... ankpn.html
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Most of the Links still work Grumpy.
For the Pontiac guys like me.


Most of the info is correct.
One area overlooked is the very high piston speeds present in 455's.
Much like a 496 stroker BBC behaves.


The Grumpy Grease Monkey mechanical engineer.
Staff member
yes thats very true and one thing I found over the years is that once you exceed about 230 degrees at .050 lift the tighter 106-104 LSA cams tend to work better especially with the dual quad intakes, provided of course that the headers and exhaust behind them are designed to enhance cylinder scavenging and the compression is up above about 10.5:1
tighter LSA in a 428-455 really help with the torque , but don,t go for too much duration 6000rpm is fairly high rpm with a pontiac



ultra rare MT pontiac hemi


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Birdman is running a Shaker Hoodscoop.
The enduring feature is also an achilles heal.
He has a ways to go to be finished.
His goals are different than mine.
He needs Top end HP to hit 200 mph or close.
Dual Quad be best I agree.
Will fit nicely on a GTO


solid fixture here in the forum
Staff member
9. 160 thermostat ? I thought you recommended 180 to promote "drying out" the oil + drill a few small holes to get faster action...


The Pontiac Guys have their own Forums.
Much is not Google searchable .
Have to join them to see and read daily.
This Data is over 20 years old now.
Much applies yet.
There are 500 CFM intake Port Pontiac V8 heads out now to Fit 455-600 ci Pontiac V8 engines.


reliable source of info
The list in the OP has a lot of good info for drag race.. Some incorrect or not applicable to all Pontiacs though.

List says using a T-350 instead of a T-400 reduces unsprung weight. It's actually SPRUNG weight.

List says "Pop up the back portion of the hood to allow hot pressurized air out of the engine compartment." Which can sometimes help with cooling or aero on cars which have a cowl panel between rear of hood and windshield but can be dangerous on cars with a hood that extends to the windshield. High pressure air at the base of the windshield is forced into the engine compartment (reducing cooling) and then flows under the car which can cause the rear of the car to get "light" on the big end at the strip (in fast cars) causing a spin if throttle lifted quick or too much brake too quick.


The list in the OP has a lot of good info for drag race.. Some incorrect or not applicable to all Pontiacs though.

List says using a T-350 instead of a T-400 reduces unsprung weight. It's actually SPRUNG weight.

List says "Pop up the back portion of the hood to allow hot pressurized air out of the engine compartment." Which can sometimes help with cooling or aero on cars which have a cowl panel between rear of hood and windshield but can be dangerous on cars with a hood that extends to the windshield. High pressure air at the base of the windshield is forced into the engine compartment (reducing cooling) and then flows under the car which can cause the rear of the car to get "light" on the big end at the strip (in fast cars) causing a spin if throttle lifted quick or too much brake too quick.
Yes its mainly Drag Race Info Birdman.
Road Race has different requirements.

The Record setting Super Stock 1969 Pontiac Trans Am RAIV that Ran High 9's in 1/4 mile with Bone stock unported #722 Round port heads,
had a Turbo 350 transmission installed.
4.33 rear diff gears in the stock 8.2" 10-bolt.

The next closest was a 1968 RAII Firebird with stock round port heads.
4- speed Muncie transmission.
Low 10's 1/4 mile.


reliable source of info
Both things I mentioned apply to drag race as well as road race, open road race, land speed racing and street use.


The Grumpy Grease Monkey mechanical engineer.
Staff member

A 1966 GTO fitted with cancelled ‘8-Lug’ wheels is featured in a Pontiac sales film
Thomas A. DeMauro on at 2:58 pm


Still image from video below.

The 1964 GTO appealed to a power-hungry baby-boomer market and easily exceeded its sales projections. A new nose and tail and higher engine output made it even more popular for 1965, but in the following year, a sales record was set. For 1966, the GTO became its own series. Thanks to modernized exterior styling and revised instrument panel and bucket seat designs, as well as an expanding performance image, 96,946 were sold.

Coke bottle side styling and a recessed backlight, with sail panels that provided a semi-fastback silhouette, adorned the new body. Reshaping the bumper, the blacked-out split grilles and the headlamp bezels further integrated the front end appearance. Parking lamps were set into the grilles, and the hood scoop returned. Louvered taillamps and a bowtie-shaped rear completed the look.

A 335-hp 389 engine with a 10.75:1 compression ratio, Carter AFB carburetor, 273/289-degrees advertised duration and .410/413 lift camshaft, and dual exhaust were standard. The optional 360-hp Tri-Power engine added three Rochester two-barrel carbs on a matching intake manifold with open-element air cleaners and a more aggressive 288/302-degrees duration and .414/.413-inch lift cam.

An over-the-counter Ram Air package for Tri-Power engines featured an open hood scoop ornament, a pan, a foam gasket, 301/313-degrees advertised duration cam with .413/.413-inch lift and heavy-duty valve springs. It could be factory built later in the model year with required drivetrain components.

Though a column-shifted three-speed manual was listed as standard for GTOs, a heavy-duty floor-shift three-speed and the Muncie M-20 wide-ratio and special-order (with 3.90 or 4.33 rear gears) M-21 close-ratio four-speeds were optional. Also extra-cost was a Super Turbine 300 two-speed automatic.

Depending upon engine and option choices, the 8.2-inch 10-bolt rear end could house gear ratios of 3.08, 3.23, 3.36, 3.55, 3.90 or 4.33. The extra-cost Safe-T-Track (limited-slip) was required with 3.90s and 4.33s and available with all other ratios.

The 115-inch wheelbase perimeter frame (boxed with the convertible or the HD frame option) and the general suspension design was shared with Tempest and LeMans and GM’s other A-bodies. To improve handing, the GTOs received heavy-duty coil springs and specific shocks in the short/long A-arm front and four-link rear suspension systems. A thicker .938-inch anti-roll bar was used up front. An optional ride and handling package firmed up the suspension even more.

A set of 7.75 x 14 tires was mounted on painted 14 x 6 steel wheels with hubcaps, but extra-cost wheel covers or 14 x 6 Rally wheels were also available.

Part of what made the GTO so popular was the wide availability of performance, comfort and appearance options that allowed buyers to equip their Goats to suit their exact needs. Though it had many positive attributes, one area in which the GTO was lacking, as many who have owned one can attest, was in braking. The 9.5-inch four-wheel drums were marginal, and while optional metallic linings and aluminum front drums helped somewhat, they didn’t compare well with front disc brakes, an option that was still a model year away for the GM intermediates.

One idea Pontiac had to bridge the braking gap was to modify it’s often praised 14-inch aluminum drum integral hub (commonly referred to as 8-Lug) wheels, which were optional on the full-size car lines, for use on its intermediates. The big-car wheels consisted of a finned aluminum wheel hub/brake drum (with an iron liner) that bolted to a steel outer rim via eight lug nuts and was dressed with a center cap and trim rings. Since there was no wheel covering the finned drum, heat dissipation was increased and brake fade was reduced.

Possibly in an effort to keep the cost reasonable, however, Pontiac determined that the integral brake drum would be cast-iron for the intermediate models instead of aluminum. The mid-size car version also featured three fins between each lug nut instead of two.

The 1966 dealer brochures and the performance brochure show these wheels as optional for the GTO and LeMans. They are also mounted on the subject GTO featured in the sales film that accompanies this story. The dealer brochure mentions that the “integral wheel and drum assembly [wheels] are not available at the start of production.” The buyer is instructed to, “Check with your dealer for availability.”

Unfortunately, “Pontiac Parts and Accessories P&A Extra” No. 66-2 that was released on January 12, 1966 contained bad news. It stated that the wheel option had been cancelled and they had never been used in production. The part numbers were 9785219 for the front hub and drum assembly, 9785223 for the rear drum and 9785225 for the wheel.

Though there is interesting general sales information provided in this film, what makes it a gem is the fact that we get to see a 1966 GTO in action with this integral wheel-brake option that wasn’t released to the public.

So sit back and take 3 minutes and 40 seconds to learning about the 1966 GTO, and see how cool it could have looked with 8-Lugs.


The Grumpy Grease Monkey mechanical engineer.
Staff member
I have a good grasp on both reality and experience, and dealing with machine shops,
before you jump into any project do the required research,
think, do the calcs, price parts, talk to your local machine shop,
get out that legal pad calculator and make the required inquires and phone calls
and I have to point out I have zero brand loyalty,
as an engineer Im concerned more with cost and potential results per dollar spent
Id rather build Chrysler/ MOPAR first and second gen, hemi's than any other engines
if you check carefully, on a dollar per horse power, basis,
I don,t build many Chrysler/ MOPAR engines for the same reason you probably won,t want to build Pontiac's
you can build a darn impressive BBC with significant horse power for less total cash outlay.
than a similar horse power Pontiac.
now Ive built plenty of both engines and I have no problem building either one,
if you want under 500 hp the SBC or CHEVY LS is the route most people take.
yes you could build a 500 caddy, 455 buick, or BBO (OLDS)

either more common, pontiac or BBC engine family can be built to run well,
and the BBC and pontiac engines have a great deal of potential,
the results you can expect are based partly on your checking account balance,
and the skill and knowledge of the local machine shops
but Id point out, you can find more good aftermarket parts , at a reasonable price at swap meets,
far more often for the BBC, and whats even more important,
you have a far wider selection of O.E.M. and aftermarket parts too choose from,if you select a BBC.
Id bet 3/4 of the current after market manufacturers no longer produce Pontiac V8 parts
yes you can build either engine family, but your wallet will hurt a bit less per horse power gained with a BBC,
unless you already have significant pontiac parts and GOOD QUALITY pontiac parts and,
you are willing to be limited to what those parts can provide.
theres zero doubt Pontiac made some good engines, but theres currently,
a limited and shrinking base of salvage yard engines.






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