Reducing the "throw" of the pressure plate may have the opposite affect,
you may actually reduce the clamping force, this is especially true with
center force clutches because of the warped disk spring design, not so
much with the coil spring type plates, but the thickness of the clutch
plate has a lot to do with clamp forces.
If your clutch is starting to slip, get a center force plate and a good
disk, stay away from the feramic (sp) type disks as they do not slip
when you ride the clutch, this is bad for driveline parts
Wild