The three finger one is probably a Borg & Beck type [ could be a Long type ] and was the type used by the factory. The one with many smaller fingers is a diaphragm type. The Borg & Beck will very likely make for a stiffer pedal and will require that you keep the pedal overcenter spring in place in order to keep the pedal effort reasonable. Borg & Beck type clutches tend to be very reliable which is why the factory used them. Diaphragm clutches give a lighter pedal feel and can work quite well IF they are well designed. Centerforce,McLeod, and Sachs all make good diaphragm clutches. I don't know anything about the Ztreeter clutch. Improperly designed diaphragm clutches lack holding power and tend to hang up at high rpm. Some people remove the overcenter spring when using a diaphragm clutch, but this isn't necessary if you install a positive stop on the clutch pedal to prevent overcentering. The choice is yours.