dunno...i mean, there are lenty of kits available to do a sbc, and no doubt it'll produce more power at a lesser price. i have seen m6x e30's though, so i am sure it will fit.
for me, i would probably drop in a german v8 over a domestic, as absolute highest hp is not my end game. i'd rather have something that looked factory and handed well.
besides, no swap like this is ever 'easy'.