The heart and soul of the car starts with the big block 428 cubic inch V8 Police Interceptor. This motor featured a 10:1 compression, high lift cam and a pair of 600 cfm Holley four-barrels with progressive linkage and vacuum secondary's on an aluminum medium rise intake manifold. It was rated at a conservative 355 horsepower but Shelby enthusiasts claim it actually pumped out some 50hp more while generating 420 lb-ft of tire scorching torque. For 1967 Shelby Mustangs got progressive rate springs that were comfortable on the freeway but stiffened as they were compressed to give good handling. The 1967 Shelby Mustangs came with the full complement of scoops as well as unique fiberglass hood, nose and rear deck. 15x7 wheels were standard with the Goodyear Speedway tires. This Mustang on steroids filled the bill perfectly and outsold the 1967 GT350 by nearly two to one.