The car was born in 1962 as a Ford-powered challenger to the Corvette when Shelby, a Le Mans-winning race driver sidelined by a heart condition, decided his future was in building fast sports cars rather than racing them.

Ingenuity met opportunity when England’s AC Cars discontinued production of its Ace sports car because engine supplier BMW stopped making the 2.0-liter inline six-cylinder engine that powered it.

Ford Motor Company’s compact, lightweight small block V8 debuted in 1960 with the arrival of that company’s new generation of unibody models like the Falcon and the Fairlane. Shelby thought the 260 V8 would fit into the Ace’s engine bay and that his racing connections at Ford would permit him to get the engines for what would become the Shelby Cobra.

Bolting a 260-horsepower V8 into an obsolete British chassis produced a fast car—with a top speed of 140mph—but not one with tolerable ride or handling. Boosting the power with the 271-horsepower, 289 cubic-inch engine in 1963 only exacerbated these problems.

“There I was, with all that Cobra horsepower, and the rear wheels were bouncing and leaping around so badly that I could barely keep the beast on the road,” reported a Car and Driver review in the magazine’s test of the early Cobra.

Naturally, Shelby’s solution was to put in an even bigger engine! However, Ford’s monstrous big block 427 “side oiler” engine would never fit in the AC frame. To accept the 427’s massive bulk, Shelby’s team designed a new chassis with wider, stronger frame rails, upgraded coil spring independent suspension, and more precise rack and pinion steering in place of the flimsy frame, leaf spring rear suspension, and recirculating ball steering.