An accurate 8 3/4" rear axle width list

I just picked up an 8.75 LBP housing and axles for my 73 Dart swinger at Mopars in the Park. It did not come with backing plates and I am thinking the original 7.25 shock mounting plates will have to be swapped out also. I haven't checked axle tube diameters. I'd like to run 10 inch rear brakes. I am assuming 10 inch backing plates off any 8.75 will bolt up to the housing, but do I need to worry about shoe width. should I be concerned about this?
Yes and no. Width matters so pay attention. Backing plates usually interchange. Though Your best bet is to get a back plate drum set.

No the 7.25 mounting plates will not work in your new 8.75. 2.25 inch diameter tube versus 3 inch. I tried to hog my plates out but the shock mount itself hit the axle.