Off the top of my head, I remember what a pain in the neck it is to install the gas pedal. You've got to be lying on your back, head way under the dash, you slide the pin thru one side of the pedal into the shaft, thru the spring and out the other side of the pedal. My pedal had a groove where one of the spring arms would lay and there is a groove in the pin to hold the spring and assembly in place. I might be doing something wrong because my pedal fell off about a month ago.
70 Chevelle SS509 "Something wicked this way comes"