I am currently having my old 3:09 rear end changed out to a 3:73 rear end non posi. It's a 80 Camaro Z28. Just want to see what kind of change to expect? Is this going to be a big difference or just a small change 1/4 mile time?

 

small change a 373 is a good all around gear and probley the best street car gear so you can still go on the free way without any trouble i got a 410 in mine but it runs 9s and isnt realy a street car

 

why did you get a non posi? while your getting the rear end changed out, you should have a posi put in, it will make a difference too

but i agree, 3.73 is a great street gear, gives a better launch and still get ok highway rpm's

do you have a 4 speed 80z28guy?

 

Great choice for a street car, and the posi can always be added later if your car needs posi for traction control. Most stock engines wont have traction issues without posi, but if it's built it will be a one wheel wonder!

 

The car has a 4-speed. It have some mods done. Elderbrock intake, Headers, Carb, Cherry Bombs, MSD coil/dist and now 3:73 rear end.

I didn't have much traction problems with the 3:09 rear. So I'm just kind of wondering if the car is going to light it up pretty good now. I can always add traction bars later.

Baby coming cheap rear end out of a 80 Trans Am got it for $100 bucks.

Going to take it to the dragstrip to try it out next week in Epping NH.

 

oh wow nice! i haven't seen one that cheap locally but i have seen some nice trans am rear ends for only like 300-400

oh well that 4 speed will def help with the rpms on the freeway too..you should but doing the same rpms with your 4 speed and 3.73 gears as you would with like a 2.53 because of the 4 speed..and your launch will be better..well is your engine the original engine though besides the mods?

 

The 4 speed wont be any different than any std. 350 or 400 turbo at cruising speed in 4th gear. Once you're in 4th it's 1-1 ratio, so they're all the same then. A 5 spd. or 6 spd. will give overdrive, but not a 4spd or automatic of that generation.
If you had no traction problems before, you shouldn't have any now with 3.73's as the rpm's will catch up quicker with the lower geared rearend. You should turn a little quicker times though, and probably feel a little more acceleration.

 

oh i assumed that the 4 speed had an OD..my bad lol

 

The engine is original but rebuilt. I think the body has 140K on it and the rebuilt motor had about 20K on it. Not sure what it has for a cam. So that is another project for next year. What would be a good upgrade next? I just don't want to waste money.

 

that all depends on what you would like the car to be its your car,do you want a street car a race car a nice driver and what you can aford to pay