In 1964, he drove with Ken Miles at Sebring in the prototype 427 Cobra CSX2196, aka "The Turd" for Shelby American Racing.
Lacking a FIA Federation Internationale de l'Automobile license Miles wrote a letter of recommendation to the race sanctioning body on the spot.
In 1985, Jim Busby hired John as team driver in one of his BF Goodrich sponsored Porsche 962s with Pete Halsmer.
Morton was third overall in a Joest Porsche in 1986 and class winner in a BFG Mazda Lola in 1984, competing nine times at Le Mans.
He made his CART debut in the first race of the 1984 season at the Long Beach Grand Prix and finished 9th but was never able to get a ride in competitive car.
Currently most of John's competition is in vintage races driving a variety of cars, which include Cobra coupes, Corvettes, Porsches, and a Sunbeam Tiger.
In 2010, he suffered a crash when his Scarab flipped end-over-end near turn two of Mazda Raceway Laguna Seca, landing upside down with a broken roll bar.