First introduced in 1966 as a variant of the 1965-1966 Ford Shelby Mustang, the GT350H was the result of a deal between Ford and the Hertz rental car company, to create a high performance rental car. For 1966, these cars were powered by Ford's "K-Code" 289 'HiPo' V8 engine, which was modified by Shelby to produce 306hp. This engine powered the rear wheels through a 4 speed manual or  4 speed automatic transmissions. Once these cars reached the end of their rental lives, they were returned to Ford, who then refurbished the cars and sold them under the GT350H guise. While some have been painted in different colors, a large percentage of the original Hertz cars were painted black, with gold stripe work. A total of 999 examples of the 1966 Ford Shelby Mustang GT350H were built, with the GT350H name returning later in the Shelby Mustang's life as the 1968 Ford Shelby Mustang GT350H.