stock rearend gear for 97 Z28 auto

[z28trick]

my 97 has an automatic trans and i would like to know what the stock rear gear is. i think it is a 2.73 but i am not sure..also i would like to know how many splines the axle has on it and what size ring gear. i think that is 7 5/8.

[flatlander757]

It comes with either 2.73 + an open differential

OR

3.23 + posi differential

You can tell by looking at your option codes in the glovebox or doorjambs:

GU2 = 2.73
GU4 = 3.08(non Y87 equipped 3800 V6 cars)
GU5 = 3.23
GU6 = 3.42(all M6 cars)

I'm not sure about 97, but in 94 at least, you can tell by the shifter because 2.73s came with a shifter plate that did not let you select first gear manually, but the 3.23 cars COULD shift into 1.

edit: ring gears are 7.5"

not sure about splines.

[z28trick]

alrighty thanks..im gonna redo the whole rearend sometime in the near future. my car has the 2.73 gear stock because the shifter doesnt have the first gear position...however i had it in second and snatched on that motha and broke the plate so i have first gear now