The partnership between Ford and Carroll Shelby is regarded as one of the most important and prominent in motorsport. This partnership was built around collaborations such as the Shelby Cobra, the Shelby Daytona, and various very successful racing programs. With its debut in 1965, the Shelby Mustang GT350 was the first time the American masses had access to a product of that collaboration. As the first variant of the 1965-1966 Ford Shelby Mustang, the GT350 introduced the public to the performance capabilites of Shelby American. The 1965-1966 GT350 was offered in a fastback coupe body style and was powered by Ford's "K-Code" 289 'HiPo' V8 engine. This engine was modified and tuned by Shelby to produce 306hp, which drove the rear wheels through a 4 speed manual or 3 speed automatic (1966 only) transmission. The 1965-1966 GT350 was replaced by the 1967-1968 Ford Shelby Mustang GT350.