Does anyone know what the difference between a 7 5/8" rear end and a 7 3/4" rear end?

[Jerriko]

I got this rear end off of an 87 GTA. It has brand new rear disc calipers, pads, e-brake cables and had synthetic gear oil. Someone took really good care of it. Problem is that is has 3.27 gears in it. I would prefer to have 3.73 but I can't seem to find any 7 3/4" rear ends in any of the parts catalogs. I already have a set of Richmond 3.73 gears but they are for a 7 5/8" rear end.
Thanks,
Jim

[speedy-v6-camaro]

1/8"

[njspder]

if it has 3.27 gears it is a 9-bolt, not a 10-bolt rear(10bolts had 3.23 gears). the 9bolt is actually a stronger unit but parts are more expensive and harder to find.
do a search for 9-bolt on google, there is a place called 9bolt resource or soemthing like that.
or do a search on thirdgen.org, 9botl questions come up all the time over there.

later
tim