Help I don't know how to find the gear ratio for the rear end so i can send that info to http://www.pcmforless.com/ for PCM reprogramming.

 

is it stock? 6 speed or auto?

 

1994 Z28 Lt1 350 4L60E auto 4spd tranny STOCK ( for now ) Sorry i didn't get that in on the start.

 

The specs of your car doesn't mean a thing. You can find out what gear ratio the car may have come with from the factory. But that doesn't guarantee that's what you still have, things can change.
Jack the back tires off the ground, and put the trans in neutral. Make a reference mark on one tire and on the pinion yoke. Turn the tire one full revolution while also counting how many revolutions the pinion makes. For instance, if the pinion turns 3.25 times, the ratio is 3.23:1 (or the nearest available gear ratio depending on your results).
You have a limited slip rear, so both tires would be spinning in the same direction. For someone with an open diff, you would jack only one wheel off the ground to determine the ratio.

 

look in the glove box at the codes in there...you're looking for GUx. give us that number and we can tell you the gear ratio

 

It's been a long time ago I herd that but i wasn't sure about one tire up or both. Clear now THANKS !

 

I will check and give you that so we can compare both methods, but it will be Sunday before i can get back to you on that whammer3024, outa town a couple a days. Thanks !

 

pretty sure on an open rearend if u turn one tire with the other on the ground the shaft will turn half the number of times than if u turn both wheels at the same time. 323 would turn the driveline 1.6 times.

 

Pretty sure what you are referring to is when both the wheels are off the ground. The open diff spins one wheel in one direction and the other wheel in the opposite direction, splitting the rotations at the r&p in half. It's been a while since I've messed with an open diff. Anybody wanna do a test?
To avoid any question of axle rotation differences, turning the driveshaft instead of the tire would be a more accurate way of doing it. That way the differential isn't doing the driving, it's being driven like normal.