If you make your car hook up well it will break the 8 3/4, especially with mild street and strip motor
Been there done that way to many times
Stop now and sell the 8 3/4 and buy a Dana 60 with a posi and 35 spline street axles, not race axles.
Call Cass at Dr. Diff. at 406-883-4772 and tell him Cab said to call to place your order.
He will have a bunch of questions on how you want your rear end built like width, spring pad placements, which brakes you want and so on. He is good to work with and good on prices and very smart on rear ends