The 1967 Shelby GT500 had an engine displacement of 428 cubic inches.
Shelby based the first GT500 on the 1967 Ford Mustang and equipped it with Ford’s FE-series 428 Police Interceptor V8. The engine used an aluminum mid-rise intake manifold and two four-barrel Holley carburetors. Shelby rated the combination at 355 horsepower and 420 pound-feet of torque, giving the GT500 considerably more muscle than the regular Mustang range.
The 428 figure describes displacement, not horsepower, engine code, or model year. It is also a cubic-inch measurement: 428 cubic inches is approximately 7.0 liters. The 1967 engine should not be confused with the later 428 Cobra Jet, which Ford introduced for the GT500 in 1968 and which led to the “King of the Road” GT500KR.
Shelby produced 2,048 examples of the 1967 GT500. The model’s dual-quad V8, fiberglass body components, and distinctive front styling made it one of the most recognizable high-performance Mustangs of the 1960s.