How much money are you willing to spend?
Without major machine shop work the answer would be 3 7/16" pistons and no on the crankshaft.
However I have a C and a B with modified D-15 crankshafts in them. I modified the main bearing journals as well and changing the stroke to 4 inches rather than the 3 7/8 inch stroke. I bored the block to take larger sleeves also. I am glad I did it but would never spend that kind of money again. I only did it in the first place to prove that it could be done to myself.