Is there any way to tell if your Rear Diff is the rare 8.5&a

Blaze One · Post by **Blaze One** » Mon Jul 17, 2006 4:22 pm

Moved to NOS since the crew cabs did not have a 8.5" diff-HJ

I have notice that a few NON ZR2 S10 based 4x4 AND 2wd trucks/suv's have the 8.5" rear diff. Instead of the "regular" 7.65" diff .

Is there anyway to tell which one is there , just by the outside cover ?

I guess you could compare it to a Zr2 diff . But I can't fnd a good clear picture of one .

Any thoughts ?

Post by **HenryJ** » Mon Jul 17, 2006 4:44 pm

The 8.5 cover is rounder than the 7.5 and 7.625. It is pretty easy to tell once you have seen both.

Zr2.com used to have a good picture.

Here ia a Camaro cover-

That gives you kind of an idea.

Jigg · Post by **Jigg** » Mon Jul 17, 2006 5:39 pm

Here's my 8.5" :

Post by **Walt** » Tue Jul 18, 2006 6:35 am

killian96ss · Post by **killian96ss** » Tue Jul 18, 2006 7:51 am

The gaskets show the differences pretty well also. Like Brule said the 8.5" is more rounded than the 7.5" or 7.625".

8.5" 10 bolt gasket.

7.625" 10 bolt gasket

Steve