I don't believe that is an 8.5, the 8.5 will have the larger round pinion yoke. Plus nowhere in the description does it say its an 8.5, and says it fits a Bravada, and NONE of the Bravada's ever had the 8.5 from the factory.
If u look real close the axle tubes look like they bulge out of the housing a Lil and as far as I know I've never seen a 7.6/7.5 with those same leaf spring perches. The seller may not know he has an 8.5 like many people out there. Only way to be 100% is to see the lugs on the pumpkin and to contact the seller. I just posted this for some who is looking for an 8.5, maybe they luck out & get 1 for what it's listed. I think it's an 8.5 but I would want to see more pics of those tell tale spots if I were to buy it.