Im pretty sure this has been asked a million and a half times by now. But I searched and couldnt find anything so here goes.

Whats the difference between an SR N/A and an SR turbo head? Off the bat, I know cams will be different.

Will the head off of a rear wheel drive SR fit the block of a front drive SR?

What sort of differences are there between the block of a rear drive and front drive SR?

What is preventing me from mating the two, be it a turbo or N/A rear drive head and a frond drive block, and putting it into a rear drive application?

Any information will be useful. Thanks in advance.