GeoffSprintGT had asked: "what parts one needs to do the conversion properly?"
Well, basicly you need the pedal box from a '69 (of course with all the pedals and rods), the clutch MC, and the rigid lines that plumb the MC to the reservoir and to the clutch slave. You will also need either a 2nd reservior, or one with two bungs (one for the brake, the second for the clutch). And, you need to modify your frame rail by cutting the large hole that the clutch rod to passes through, as well as drill & reinforce the holes that the MC bolts through.
He went on to say: "I think the clutch on my car was converted, however the pedal is very very stiff, I was thinking that it was because the clutch was going but a mechanic told me it was probably due to the pedal not being correct. Also more reciently, the clutch has been slipping, almost like the pedal looses pressure, and if I pump it, it gains its pressure."
Sorry, don't have enough information to give a meaningful reply. The difference in pedal length that I observed - about 1/4" - wouldn't be enough to result in stiff operation if a shorter pedal were substituted. I suppose the first thing to diagnose is whether the stiffness is due to a mechanical problem (in the pedal box vs. in the bellhousing) or a hydraulic one (e.g., flex hose swollen almost shut).