Body to pedal shaft alignment is critical. I had a problem with my pedal not returning to the top. The problem was the pedal shaft was rubbing on the side of the hole in the floor board.
Check it out.

1949 chev 3100 3 window. 350hp/327/m21 4 spd, 12 bolt rear, power brakes, 3" dropped axle from Sid's. Disc brakes next.