d16 crank has larger main bearings so a d15 crank will not fit into the d16 block. the d15z1 rod is a weird size as well.

BTW i might have a extra rod and piston laying around from a d16z6. i have 2 z6 motors that i took apart. i don't have any cranks left though. i have a d15 crank though but that's no good to you. depending on how bad your crank is you might just be able to have it turned.