I was wondering if my 1991 Camaro Z28 came with a 7.5" or 8.5" Rear End. From what I have been understanding it is the 7.5" . . . but my college teacher thinks that since it's a Z28 it has the 8.5".

It came stock with a 305 Engine, Automatic Transmission, 2.73:1 Gear ration, Drum brakes and Posi. And it is a 10 bolt not a 9 bolt.

Reason I ask is because I want to put a gear and locker in it but im just not sure what size it is. And since im 200 miles from home I can't drive back pull off the cover and measure it.

Thanks,

Sean

 

I'm pretty sure there were no 8.5's in f-bodies. If you have a 10-bolt it is a 7.5, if you have a 9-bolt, well, it is a 9-bolt (so give up trying to put a locker in it). If it's rear drum my bet is it's a 10 bolt 7.5. As for telling the difference, an 8.5 will have a more rounded appearance and have corners coming off of the bottom sides. The 7.5 will look a little more square and have fangs coming off of the bottom sides. FYI here are pics of the 7.5 on my caprice:

http://www.people.virginia.edu/~blr6k/caprice/diff/