7 1/4 To 8 3/4 drum brakes

if they are 10" brakes the drums are the same between the A body 7.25 and 8.75 assuming they are both small bolt pattern. The backing plates have different offsets and can not be interchanged.
Personally I wouldnt bother with the small bolt pattern stuff unless I had to.
Buy a new set of large bolt pattern axles set up for the standard MOPAR brake offset and use any large bolt pattern rear brake set-up. 7.25 to dana, it all swaps.