In my experience, the clutch reduction effort kit is helpful on the long throw clutches and may work against you on the diaphragm clutches. At one point I had two Pantera concurrently and actually pulled the kit out of one of them and added the kit to another. The one that I added the kit to was a long throw and it took incredible effort to press the clutch pedal. Once the kit was added, the clutch was wonderful. In contrast, a diaphragm clutch with a hydraulic throwout bearing was very difficult to use with the clutch reduction kit. The clutch seemed to be on or off and made it easy to stall the car when taking off at a green arrow for a left turn. Removing the kit on that set up made the clutch very nice.
The factory clutch reduction effort kit on the later Panteras are mostly worn out by now. A couple of the holes in the mechanism tend to become oblong and the kit does not work correctly. A fresh kit is available from our vendors that has roller bearings where the original kit simply had holes in the steel plates.