gsl

got a12r motor from corona 1974? put it in to my hiace rh11 1979/80, had 12r motor originally. put original gearbox and clutch from rh11 on, went on easily enough but throwout bearing doesn't seem to engage or reach pressure plate. do i need different gearbox from corona, adifferent release/throwout bearing, or different clutch kit, tried it all twice, adjusted etc, can't seem to get it to work, what am i missing? a part or a brain, please help!