I just bought a 9 bolt for my car, and want to get some part for it. In the napa catalog, they show three rearends for my Firebird; a 7.5" (obviously, the stock 10 bolt), a 7.625" and 7.75". Which is the 9 bolt?

Thanks

nine bolt=7.75

9-bolt = 7.75"

7.5" & 7.625" are the same thing, for all practical purposes, and are the 10-bolt