8.75 Brake ???

The sb drums will not fit the bb axles and thats a fact. The diameter of the axle is larger so the taper won't fit also the center is larger on the big bolt pattern axle. The backing plates for the BBp is offset farther back allowing the wider brakes the BBp drum will hit the outside of the sb Backing plate. You must use the BBp set up as a whole. Now if you drill your own axles then you can drill the drum. And that is that. So don't listen to anyone that tells you different. I have both setups off and can show you the difference. The outside diameter of the BB axles are wider to accommodate the larger bolt pattern the sb drums do not have a big enough of a flat area to cover the flange. also as stated the sb drum doesn't have a big enough center hub.