10 x 2 1/2 SBP Drum

cosgig said
How about 7 1/4"vs. 8 3/4" 10" drums, are they interchangeable??

Not the A-body stuff. Small bolt pattern 7.25 brakes do not interchange with small bolt pattern 8 3/4 as far as I know.

The BBP 7.25, 8.25, and 8 3/4 brakes are interchangeable. The BBP axle flange offset was the same across the board.