How much is to much?

8 1/4's use 10x2.5" brakes, not like the 10x1.75's that came on SBP A bodies.

But 10x2.5" rear drums came on EVERYTHING else, including pretty much every mopar up to around 1989. Not just on B-bodies.

You can easily find the 10x2.5" set ups at the local wrecking yard on Diplomats, Aspens, 5th ave's etc all the way up to '89, and sometimes after that depending on the model.