AC, a long established builder of traditional British sports cars, had been building a car called the Ace but was about to lose its engine supplier. The engine was a pre-WWII, BMW designed six cylinder built by fellow English sports car marque Bristol.

At that time Carroll Shelby, a former racing driver, approached AC with an interesting proposition to replace the smaller engine with an American built V8. He first approached Chevrolet, who turned it down worried about the competition with its own Corvette. Ford stepped in and relished the opportunity to take on the Corvette in the racing circuit and they supplied the mighty 427 cubic inch V8 for Shelby to use.