Can't tell you in hard numbers. The factory effort-reduction 'kit' is actually an over-center linkage similar to that used on compound bows-and-arrows. With the kit, pedal effort is slightly HIGHER initially but falls off rapidly as the pedal travels further. I saw one Ford description that said it was primarily aimed at easing the effort of holding the clutch in at stoplights (with the trans in gear presumably)- a recipe for disaster IMHO. This assembly was installed in all Panteras built after July 1, 1972 and has never been available separately from a car, so the only known source would be from a totally wrecked Pantera. It requires the dashboard to be removed for installation. IMHO, if you wish to reduce clutch pedal effort, an easier, cheaper and more effective way is to change the clutch to a diaphragm type such as a Centerforce. With such a clutch, one can almost push the pedal in by hand, in my experience.