[1] After attending Bartlett Yancey High School in his hometown of Yanceyville, Gunn studied mechanical engineering at the University of Miami.

His father ran a Ford dealership near the Virginia International Raceway, which gave him access to motor racing early on.

He entered his first races during his student days in an Alfa Romeo Giulietta Spider, winning two national sports car championships.

[1] Gunn's professional auto racing career began in 1968, which led to participation in Formula A, Can-Am, and IMSA events.

[2] Gunn finished the 1974 racing year sixth behind Brian Redman, Mario Andretti, David Hobbs, Eppie Wietzes, and Brett Lunger in the SCCA/USAC F5000 championship.