you can install rod and piston assemblies on either. but, again rebalance (to do it right).
you can do a bottom end boogie mag to LA straight across even.
the difference is the pinboss in the pistons and the small end of the rod-- LA wider, mag narrower. so it's keep it matchy-matchy or skinny up LA rods to fit mag pistons.
if you change components, you change the bobweight and it needs a rebalance.
totally not confusing at all, right?
oh, and don't forget... the rings are different too...