Hey, I've got a 91 GTA, L98. I DO have Posi, so do I have a 9-bolt or a 10-bolt?
Also, I have 2.73s, and was also wondering what I should expect in instalation/perfomance if I was to step-up to a higher gear ratio.
One last thing, (I know this comes up alot but..) what would be better 3.42 or 3.73? I was gonna go 3.42 but my buddy says I may aswell just slap 3.73s on. I plan on doing the intake, headers and exhaust, and later on cylinder heads, TB, etc.. (for any hp reference to the stock motor - I shouldn't go over 300-350hp by the time I'm done my mods).

Thanks for any advise.

 

get under the car and count the bolts in the rear

 

You should have a 10 bolt because I think they stopped using the 9 bolt after 89.

 

You never know, they may have had some left over. Did the 9 bolts come with 26 axle splines or 28?

 

I also think its a 10-bolt, but we're not going to know until he gets down on the ground and starts counting (bolts, that is).