Centerforce Duel Friction Clutch

Definitely do not use the overcenter spring. The high-rpm "sticking to the floor" is exactly why they need to be removed.

Make sure that his car has the proper pedal ratio (according to Centerforce, that clutch only needs 3/8" of finger movement to completely disengage with .030 plate departure). Typical B&B clutches call for more like .050-.060.

I have the 10.5" DF behind my 451 and engagement is somewhat abrupt. At first the pedal was quite heavy, but it's loosened up a little with use. Not sure what wore-in.