An accurate 8 3/4" rear axle width list

metalbender58 said
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?

The 7.25” has a smaller tube diameter, the shock plates will not work on an 8 3/4 without modification. Better to get the right shock plates.

Any 10” backing plate from an 8 3/4 will work, but you absolutely have to pay attention to shoe width. The 5x4” and 5x4.5” bolt pattern axles use a different flange offset, and 10” SBP backing plates will not work with BBP axles or vice versa. Backing plates for 10x1.75” brakes have a different offset than backing plates for 10x2.5” drums.

How to measure the offset and different measurements for the different backing plates here

Converting rear drum brakes from SBP to BBP

And the difference in the axles here