For a twin plate 7 1/4" or 7.5" clutch you will need a big turbo flywheel, it has the smallest diameter across the face, think it is 130mm not 170 or somthing similar, it is what I run on my Escos (was small turbo , flywheel had to be changed) as I have a twinplate ...

Give martin a ring at reyland, thats who I got my clutch kit through and he sorted the flywheel machining for me.