i would have to try it and see, it depends on how close the mounts are, how easy it is so sandwitch the two together and what to do about the starter motor.
but really i would have thought the GA box will be less hassle, its just the shafts and the mounts, and maybe the gear linkage.
CG is the drive shafts, sandwitch plate and the starter motor, and maybe the torque
i got quoted 500 bar for them, they must of drop their prices since i was looking, im my opinion the 135bhp i had ,had no problems going through the cut n sleeved shafts i made, i was well chuffed with them shafts lol proud or what bet they are still holding up ha
there are 4 mounts, one on the drivers side, one on the passengers side and two on the bar that goes under the engine. together they hold both the engine and gearbox.