View Single Post
Old 09-21-2021, 10:00 PM   #36
Stan Weiss
Senior Member
 
Stan Weiss's Avatar
 
Join Date: Apr 2020
Location: Phila, PA
Posts: 795
Likes: 0
Liked 734 Times in 385 Posts
Default Re: 1968 Pontiac GTO

Quote:
Originally Posted by oldskool View Post
I can't say what a stock '68 GTO would run, new.

But, I do have some numbers for a '69 RA3 366hp GTO.

Bought it new, with a close-ratio 4-speed & 3.90 gears. Since I ordered it early in '69, I ASSUME it had the "744" cam, tho I never checked it. Later in the model year, Pontiac dropped the 744, in favor of the 068. The 744 grind specs were used in the SD455 engines.

Ran it on the street for a little over 60k miles. Put it on the track in '73. Only non-stock parts were a Weber alum flywheel & clutch. No slicks allowed. Had hard compound street legal tires. Best time was 13.95, with considerable wheel-spin.

In '74, special soft-compound tires were legal. They were basically just slicks, with a couple of very small grooves. Put in a Hays steel flywheel & clutch. It would then hook up & run 13.50's. Heads had never been off. Still had the original cam & Q-jet.

Guessing that 4.33 gears would have put it in the real low 13's. But, those would not have been as street friendly.

I have never done a 3.90:1 to 4.33:1 gear change. But IMO I would be very surprised if you saw anymore than a .1 of second improvement.

Stan
Stan Weiss is offline   Reply With Quote