Individual clutch sets can vary in their feel. I've worked on Panteras that my enthusiastic 5'3" wife refused to drive due to a too stiff clutch, and I've had others with clutches you could push in with your hand. None, by the way, slipped in street driving. Any clutch titled 'heavy-duty' will likely be too stiff for the street. One common problem is, non-Pantera parts vendors see "Pantera" and instantly think "race car". This is particularly true if the car was built before the effort reduction kit, or the never-lubricated steel-on-steel parts in your kit are badly galled/worn, or the hydraulic slave system is mis-adjusted or leaking.
Proper adjustment of the clutch linkage is very important as well. Too much pre-load will work against you and the car, and too loose will cause rapid wear on the ZF transaxle synchros- you do NOT want to check on the cost of a ZF overhaul today! With all-new, lubricated parts in the entire clutch system, there's only about 0.040" of clearance between the flywheel & clutch disc, with the clutch pedal matted hard! And that tiny space is split between the flywheel-to-disc, and disc-to-clutch surfaces. You check this by having someone push the pedal firmly to the floor while someone else reaches in thru the clutch inspection/ventilation hole in the bellhousing with a long flat-blade feeler gauge.