['ol Pinion head]

-there were a little over ONE MILLION '71-72 8.5 A-body rears installed in 71 & 72 GM divisions cars.
-3 different versions of the 71-72 8.5 A-body rear were built. The differences are due to the center housing design, & whether the housing ends accepted A9 or A10 axle bearings.
- one thing ive noted many times: It's never smart to try & identify a housing by poorly written ID Guides & generalities. How many folks use the term "BOP 8.2"? No such thing, just a long time generalization. From decades of hands on experience, there were Early Buick 8.2's, Early Pontiac 8.2's, LATE Buick 8.2's ('68-70), & LATE Pontiac 8.2's. Bunch of differences over the years.

The above pictured rear is indeed an 8.5 A-body rear. Ive posted a pic of that particular style housing on here before & on BuickV8.com when I used to have time to post on that site. In my housing racks have several of that particular style 8.5 A-body housing (only accepts a round cover). Began building up the '71-72 8.5 A-body rears up in the early 90's, while not as common as the style of 8.5 A-body housing that accepts the scalloped style 8.5 cover, have built up over 3 dozen of the style with the round cover.