Rear gear ratio's

[fast.asleep]

At the risk of sounding really silly, I'm not sure what rear gears I have. My car is a '87 auto with the Z52 option. I remember reading that Z52 and Z51's had the performance rear end (3.07)but I'm not 100% sure. I just noticed a post about a stock '87 with 2.55's...

Is there an RPO # I should look for?

 

[vader86]

G44 i believe is my code for 3.07, i forget exactly the RPO for the 2.73 or 2.59s. (GM1? maybe)

Z51s in my year came with 3.07 standard, but you could pick the 2.73 option, so check it out.

 

[fast.asleep]

3.07 it is! Thanks Vader, I was worried there for a minute.

By the way, you were right about 2.59 = GM1 as well!

GH0 Rear Axle, 3.54 Ratio
GM1 Rear Axle, 2.59 Ratio
GU2 Rear Axle, 2.73 Ratio
GW4 Rear Axle, 3.31 Ratio
G44 Rear Axle, 3.07 Ratio
G92 Rear Axle, Performance Ratio

from c4vettes