So...there's this totally ricey racing game out there...but amazingly, it's good for something. Getting a relative test for cars. It lets you adjust everything from weight and horsepower to transmission and rear differential gear ratios. So my question is this...does anyone happen to know what gear ratios were in the 3-speed automatic transmissiosn of the 77 vettes, and what their rear gear ratio was?

Once I find this out, I'm gonna run another test after I try to find out the tranmission gear ratios of whatever tranny I'm gonna put in after I put in the new engine, and I'm trying to find RELATIVELY what gear ratios I should have in the rear for different race lengths.

most automatics in the 70s came stock with 308s

3.08 in the rear...what about the actual transmission gearing. accurate as I can get will help on the testing.

1976-77 Rear end ratio's
OA- 3.08 positraction
LR,OD-3.36 "
OB- 3.55 "
OC- 3.70 "
Referenced via Chiltons Manual

I don't have the transmission books with me. But what transmission do you have? i.e. TH400, TH350 etc.
Sarge

The turbo 400 is close to a 2.5:1. Including the torque convertor multiplication per GM, it's effective ratio is 5.2:1

The turbo 350 is close to a 2.75:1

be quite honest, I dunno what transmission I've got, or how to find out. dun even know which of those options for gear ratios I have, though I'm pretty sure it's the 3.08s. as for the transmission I'm thinkin about putting in...

$989.99 B&M Street/strip Transmissions, TH-400 Chevy (130-112002, www.jegs.com)

well that's it.

CorvetteRacer1977 said: be quite honest, I dunno what transmission I've got, or how to find out.

If the tranny pan is shaped like square with one corner cut off then it's most likely a TH350. If it's shaped like the state of Texas, then it's a TH400.
Sarge