Clutch pedal sticks in down position

Never dealt with a problem like this before - restored a 318 barracuda where the previous owner had put some type of racing clutch in it. It took incredible foot force to depress the clutch pedal down. I replaced the clutch with an OEM style standard duty clutch. I also put new bushings in the z-bar. Now, when I fully depress the clutch pedal (much easier to do), the thing sticks down at the bottom of the floor (only when pressed to the floor, not when partially depressed). I have a clutch return spring attached to the transmission going to the clutch fork. This condition seems to be caused by a massive spring under the dash which assists in depressing the clutch pedal. It does not seem tp be adjustable. Any advice? Do I just need to find a super heavy duty return spring to place on the clutch fork? I have done GM stuff in the past, this is my first Mopar restoration, and i have never seen anything like this before.

thanks

Jim