itsphoenix
The gas pedal hinges on a bell crank throught the pedal box. The gas pedal attaches to the bell crank with a nut on your early car (with a small bolt on later cars). Over time the attaching point of the gas pedal to the bellcrank can become loose and tightening the nut more can cause the pedal to lock up the bell crank in the pedal box bushing. To check this, back off the nut a little and see if the movement frees up. If it does, you either need to repair the current pedal and bell crank, buy new, or this is my solution.
Modified Gas Pedal Lever
You can fab this yourself or I have extras I will sell you for $50. including shipping
Craig