8 3/4 rear help

Well, not sure what you paid for it. Did he tell you it was an A-body rear or did you just take for granite, because it came out of a A-body. If he told you it was I would make him give you a little of the cash back. Either way you need a route to go. Like one said you can send it out to Moser or Dr. Diff. (Cass). Have it cut down and set-up properly and that's gonna cost you money for labor and shipping,either way it has to be done. Good Luck.