the superbike tank doesn't have a flip-hinge setup as on the monsters. it's bolted down front & rear, right? additionally, the shape at butt of the tank is different so you may run into difficulties with seat fitment against it. fuel pump's different which should be fine as long as you adapt the monster's connector to apply.
as for if the tanks are roughly the same width/shape on the underside, i'm not sure... alex o. would likely know as he recently sold a monster-shaped tank to fit on a superbike frame.