so I bought my car used, i still love it. Anyway I dont know what gears it has in the rear end and dont wanna buy new ones if it already has upgraded gears. Is there a way to check?

 

As long as you know what rpm your car stays at in a certain speed you can figure out what your gear ratio is. Just fill out the info on this web page and you will know.

http://www.tchracing.com/tech/gearcalc.php

 

what rpms are you at in 5th gear at 70? that will give you a good figure. or even at 60. and someone on the forums can tell ya what they are at... at 70 im like at 2200--2300 and when i was stock gears i was at like 1900-2000. ive got 3.73's.

 

1.Raise the rear of the car. Then as you turn one of the rear wheels, count how many times the driveshaft turns. IE 3 1/4 turns=3.27 gears(STOCK), 3 3/4=3.73's... and so on.

 

jack up the rear of the car...

marke the drive shaft longways with chaulk, like a 1" or something

rotate your tires and see how many times it rotates if the drive shaft rotates a little over 4 times then you have 4:10 gears if it rotates less then 4 but almost, more like 3 and 3/4 times then you have 3.73s if you rotate and the drive shaft it a little over 3 spins about 3 and 1/4 times then you have 3.27s(Stock on most GT) if it rotates 2 and 3/4 times then you have 2.73s(or something like that, i think i cam stock on a few im not sure)

mine came with 3.27s and i put in 3.73s

 

this site worked great thanks i remembered at 2000 is when Im at 70 in 5th, turns out I do in fact have the stock gears. Well I know whats next

 

you beat me to it, i was typing

 

4.10's, you will regret getting 3.73s. Or better yet, 4.30's. Trust me.

 

That isn't quite true. I have 3.55 rear end (for now), but before I installed my headers I was running 75 mph @ 2500 rpm, now with less restriction, I'm running 75 mph @ 2000 rpm. I wasn't expecting my rpms to drop, but they did.

I'd listen to the quys about rotating the wheels while the car is off the ground.

 

i doubt he has LTs or something in there. he'd know it if he did, and not based on his RPMs.