8 1/4 rear end w/ SBP & drum brakes

You could find 8-3/4 backing plates and drums for sbp and have the 8.25 axle shafts redrilled for sbp. And you can modify. Your 7.25 shock plates to work but you will need new u-bolts..probably cost more than a disk brake swap though. I got my bbp disk brakes for $100. Good luck