Machine 360 crank to fit in a 340 main block

Just curious if anyone has any information on the cons of milling a 360 main forged crank for installation in a 340 main block. Does the removal of the material weaken the crank? Would the crank need to be hardened after the machining?

Just wondering as I am building a 360 stroker and wonder if in the future if I want to increase power and move to a 340 main race block if my forged crank would be reusable.

Thanks