Because Ford felt that factory models like the Boss 429 and Mach 1 428 SCJ matched Mustang Shelbys in terms of performance, 1969 was the last year for the Shelby models. The Mustang Shelby GT350 offered a 290-horsepower V8 with National Advisory Committee for Aerodynamics (NACA) hood scoops, a hidden gas filler, and the sport roof from the Mach 1. The front fenders, hood, and trunk lid were made of fiberglass.