a Body / swap to b body.

"A" body "K" members are the same in 64-66.
Slant six engine brackets are different between the "A" bodies and "B" bodies. I have to assume the insulators are different, also. The factory parts manual list several different part numbers and some of those numbers are the same configuration as other numbers, but the durometer of the rubber is different. So there is no way I can tell what numbers (if any) will swap.