The second evolution of the First Generation Ford Shelby Mustang was built for the 1967 and 1968 model years. This second evolution saw the introduction of the famed GT500, which was offered alongside the GT350 and the GT350H. While these cars were commonly referred to as Cobras, 'Cobra' was only officially part of the variant name for 1968. Also notable for 1968 was the debut of the convertible body style for Shelby Mustangs, where, outside of a handful of exceptions, all cars had been built in a fastback body style. A more potent version of the GT500 was also offered for 1968, known as the GT500KR. Production of the second evolution of the 1st Gen Shelby Mustang ended in 1968, when it was replaced by the 1969-1970 Ford Shelby Mustang.