From what I know:

Blocks share same bell housing pattern, water pump housing, and oil pump mounting. Block is cross drilled for the mains, MW is not. Cranks will interchange, but the flange pattern at the flywheel is different. Cam is different. A MW cam may fit, but the MW pattern is for EIIEEIIE where the hemi is EIEIEIEI for intake and exhaust accuation.
Heads and intake are obvious. Exhaust manifolds or headers are different due to valve arrangment. I think the distributor is interchangable. Engine mounts are different.

Thats what I recall off the top of my head.