Hi there I have put a rover sd1 engine into my series 3 88 landy and would like to continue to use the original series 3box with overdrive, could any body advise me which clutch setup to use as the series 3 clutch seems to be at least 10mm short of touching and a series 2a clutch the main shaft out the box won't go through the boss on the pressure plate so when all bolted up the clutch is permanently engaged, could anyone please help???