Hi, I recently acquired a 71 dart with 318, front discs, small bolt pattern and 7 1/4 rear end. Ideally, I would like an 8 3/4 rear end but realize they are hard to come by and pricey. So, I'm set on getting an 8 1/4 but since they were used in so many early and late model Mopars, I don't know...