You can use the bellhousing. Just be prepared for offset dowl pins to center the bellhousing on the block, I use Lakewood Offset Pins, buy all there ranges of dowls, there cheap and available at any performance shop. If you go to a double plate clutch you may need to grind away some interior casting surface, usually not much, depends if there was core shift when the part was cast or machined. On the external fork, pay particular attention to the throw and pull back of the internal fork. On McLeod throwout bearings for ZF they supply a retaining spring to hold the throwout and fork together on pull back. I set it up so the back of the spring just touches the transaxle case. then you have to ad or fab the correct spacers between the throwout bearing carrier and the bearing to give no more than .100 free play between the throwout bearing face and clutch fingers. After that you can set the outside lever arm...