10 x 1 3/4 Rear Drum with Factory BBP?????

Hello! I am at a standstill in my rebuild due to the dreaded 10x1 3/4 rear drums. My car came with a slant 6 and standard 7.25 rear with BBP. I cannot locate rear drums anywhere for the 1 3/4 brake system and the stock ones are shot. My question is being that I already have the big bolt pattern, what do I need to swap the brakes over to the larger 2.5 width shoes and more readily available drums, or if perhaps im just not looking for the right drum, a replacement for the 1 3/4. Appreciate the help guys!

-Shane