[patrickt]

If it's a Tilton 74-750, or 74-875 it's the right one (I have the 7/8" one). Try backing off the adjustment on the threaded rod so that the clutch fork is not even being touched. Then lightly push the pedal to see if all the resistance is now gone. Obviously that won't fix the problem, but it will tell you if there is some sort of clog in the hydraulics.