Kalebbryan90

Ok so ive spent the last bit of my day trying to figure this out! I have a 95 formula firebird lt1 auto trans. I'm curious on my stock gear ratio so I can get a set of 4.10s and apperantly I need to know what mine is stock. but my speedo is a 155mph. My trans shows no "1" its just P, R, N, D, 3, and 2. But it will drop down into a first. If that makes sense. But ive read that 155mph has one set and if there is no "1" it has different from the 155 spedo. My rpo code in glove box is missing so I cannot refer to that. also what is a good set to get? I was looking at either ordering a set through jegs or orileys. Has anyone ever had experience with the two?

FirstYrLS1Z

iTrader: (4)

you need to find out/determine what the current gear is. you could have a 2 series or 3 series carrier and that will determine what gearset part number to order.
2.73 = 2 series
3.23 = 3 series

Kalebbryan90

yes I understand that I have to figure that out first. But I was wandering how I could go about doing so? What would be the easiest way of going about it all?

SS SLP2

iTrader: (8)

jack up the car grip the drive shaft and roll it in forward motion to take out the slack in rear place a "mark"on botton of drive shaft and a "mark " on bottom of tire then roll the drive shaft and roll it forward a number of rounds ( count the rounds) untill the tire makes a complete round, if the shaft makes about 2 3/4 rounds = 2.73 = 2 series , 3 1/4 rounds = 3.23 = 3 series ( if takes about even 3 rounds could be 3.08 = 2 series)
good luck Johnny