8 3/4 Backing plates SBP question

Dana67Dart said
FYI 7 1/4 10x1 3/4 backing plates are a direct swap.

The hole in the center of the plate is smaller on the A body 7.25 than on the 8.75. Wont fit over the axle bearing. (72 back)
7.25 plate wont fit 8.75 axle.
Shoes, levers, etc. are the same.