I am doing a ZC/Si hybrid tranny with zc 1-4 si final drive. i want to use my si differential so that i dont have to mess around tring to find out what cv shafts will fit the ZC one. However, my si tranny input shaft bearing is shot i think (i haven't got it apart yet. but it rattles really loud at about 1200 rpm. in neutral, 1-5 doesnt matter what gear clutch in or out still doesnt matter. it always rattle loud at that rpm then stops above or below it.) I was wondering if it would be a better idea to use the zc housing and put the si diff and final drive in that or put the input shaft and 1-4 into the si housing? thanx guys