I don't know if the GSX14's lump will fit, - or really why you'd want to since it has about the same power as a B12 (just at lower rpm) - but if you want a 1400cc Bandit, you can build a B12's motor that big (up to 1371cc with an aftermarket cylinder block and stock crank, stroked, you can break 1500cc)... and it would STOMP a GSX14, and probably >99% of the Busas out there.
You'll want a bigger oil cooler if you're gonna ride it on the street tho.