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

Shopping around for an 8 1/4 rear end with SBP & drum brakes. I'm in the Arkansas/Oklahoma area and would prefer to pickup if someone has one reasonably close.

Wanting to swap out the rear end on my 72 /6 Duster which has the 7 1/4 rear end with drum brakes. Planning to put in a 360 and need the more robust 8 1/4 rear end. I believe a 8 1/4 with SBP intended for drum brakes should be a "drop in" replacement (?)