The tip off is the 2 square lugs on the bottom of the case, Looking at the U-joint retention, the 8.2 uses U bolts and nuts (top), where the 8.5 uses 2 straps and 4 bolts (bottom) http://jdrace.com/content/diff_id/10b85.php http://jdrace.com/content/diff_id/10bBOP_Buick.php
A lot of the 8.5’s do have those square lugs,but not all of them. There is a different casting that came under the 71-72 Cutlass/442’s that were built in Lansing Michigan. They did not have the lugs and had a different cover,BUT all of the internals are the same. Look at these 3 covers. The top one is a BOP 8.2” 10-bolt. The bolt spacing is different and there is a notch at the top for the brake hose bracket. The one on the lower left is what came on the Lansing-built 8.5’s and you also see these in a chromed aftermarket version. The one on the lower right is an 8.5”. Notice how the holes at 12:00 and 6:00 bulge out at the edge of the cover.This cover came on the 8.5’s that have the large “A” cast into it.
Thanks Brian, Just curious, does the presence of those lugs mean it is an 8.5? Did any other rear have those same lugs?
The only other rear from that era that had a lug similar to that is the 67-69 12-boot O-axle. That one has the obvious 12 bolts in the cover,but the internals are unique to that rear.
Appreciate the expertise once again. I'm on the lookout for a diff shop that maybe is more familiar with BOP stuff. Tough to tell so I've got some calls to make and vetting to do. Sincerely appreciate the help with this everyone.
Just East of Seattle. Anywhere in the Puget Sound area would be fine by me - I don't mind driving a bit to get a quality rebuild.
oof... I got nothing. Northwest Differential Service 211 South Lewis Street Monroe, WA 98272 XO - FAB.com 2551 Cole St Suite P Enumclaw, WA 9802 Seattle 311 S. Brandon St. Seattle, Wa. 98108 Phone: 206.567.1481 Best I could scrape up. ASK them before hand if they do older muscle cars. !!
Ok, at the time this thread popped up, I asked my Uncle Budd about who he uses for rear ends. Today, he had his car club breakfast, and asked all of his other buddies. These guys are various in the type of cars they build, but they are all serious. He said they universally recommended Village Transmission in Edmonds, Washington. (425) 510-5800 I also did a bit of research on my own, and it looks like there is a place called "GN Northwest" in Everett Washington that uses this picture: They appear to be a Father/Son general auto repair place with stellar reviews, and I am guessing they could help you also. 9329 Evergreen Way, Everett, WA 98204 (425) 512-9881 And here is another Father/Son in Graham Washington. https://seattle.craigslist.org/tac/ptd/d/graham-rebuilt-chevyoldsbuickpontiac/7592883138.html (253)370-0086 Hope this isn't too late.
