They are interchangeable, as the blocks are the same (actually, all the internals are the same but the pistons. Rods, cams, etc. are all the same). But, Nissan put in some other sensors for the S/C trannies to see if the S/C was overpowering the tranny at any point. If it saw too much slip, instead of toasting a trans, it would kick the boost off. Something to consider when adding power.