referring to pre98 cg10
i put a ma12 box on a cg13 with a cg10 flywheel. Not sure about the other way round, I think it would fit straight on. I think the cg10 flywheel has a different bolt pattern than the ma12, although I think the clutches are the same. Not 100% on that. Not sure the gear linkage is the same, nor the starter motor, although the ma12 bits might still fit.