What the nuts do is simulate continuously stepping on the clutch pedal so as to keep the pressure plate retracted. The levers are kept inside the housing and with the pressure plate retracted, that allows the entire assy to slip up past the clutch plate and TOB easier as well as to be able to insert and tighten the retaining bolts to the flywheel without fighting the springs as much. There is not a lot of clearance in the 356 bellhousing once the TOB and fork is in position.