Just make sure the new axles are set up for 10x1.75" brakes, the offset on the axles IS different. Then you could just have the drums re-drilled.
However- A bodies are the ONLY mopars that run 10x1.75" brakes, and they only had them on the SBP cars. Recently, there have been issues with the supply of new brake drums in this size. Plus, every time you buy new drums you'll need to have them re-drilled.
Personally, I would just get the larger brakes. Better stopping power, no worries about needing to get them redrilled, and literally MILLIONS of mopars run the same exact set up, so no supply concerns down the road. They're easy to find, and cheap. Every wrecking yard has at least a few cars with the exact set up you need.
I went a step further, I run 11x2.5" brakes on my cars. Not offered on as many cars as the 10x2.5", but they came on a lot more cars (and some trucks) than just the SBP A-bodies, and with larger modern tires they really provide some whoa power, which is handy considereing all the morons out on the roads with their cell phones.
