Backing Plate Differences

Dana67Dart said
SBP 7 1/4 has a smaller diameter center hole, bearing is smaller, than 8 3/4

In the last 3 years someone posted a photo of a SBP, 7 1/4, 10 x1 3/4 backing plate next to a SBP, 8 3/4, 10 x 1 3/4 backing plate, center home was different.

Hmmmmm. When I get home Friday I’ll measure what I have. I’m 95% sure I checked the hole size when we swapped out the axles and they were the same.