7.5 or 7.625?? - Third Generation F-Body Message Boards

MustangMuncher · 03-12-2004, 07:33 PM

Does anyone know how to tell the difference between the two sizes of ring gears? The rear end I have is a 10 bolt out of a 85 iroc 3.42 with disc brakes and was an open diff. I have ordered a powertrax unit but I dont know what size gear I have for sure. It is also has 26 spline axles.

jonarotz · 03-12-2004, 09:40 PM

I would just about swear on it that you have the 7.5. If I remember right they switched to 7.625 in 89 or 90 along with the 28 spline axles.

ede · 03-13-2004, 07:04 AM

they're the same, gm changed the name or how they ID them, nothing else is differant, or they both interchange.

MustangMuncher · 03-13-2004, 10:04 PM

Come to find out after giving it a good bath on the inside they stamped the ring gear. 7.625 was in it. But on the 89 rear end I dont see it stamped anywhere. Jegs told me as well that full size cars were the only ones to get the bigger ring gear but I guess there is no way of really knowing unless its stamped or you measure it. Thanks though

ede · 03-14-2004, 08:27 AM

don't think i'd believe everything jegs told me. they don't even list a 7.62 ring gear from richmond or jegs, all 7.5, because they're all the same.