64 dart four speed

I've got an original 64 dart / 273 / 4 speed. It's a survivor car out of montana with about 115,000 miles. The motor runs great, but when really pushing the acceleration, I can feel a pretty strong vibration in the clutch pedal. The shifter feels fine. As good as the car runs, it doesn't seem to transfer power to the rear wheels too well. When cold, the clutch really whines before getting the car into gear. Any suggestions? Is it simply a need for a new clutch? I've never noticed any slipping.
Thanks for any advice. Dave