1968 was the first year of the convertible for the Shelby Mustang. 1968 also saw the introduction of the GT500KR, which meant 'King of the road'; a moniker borrowed from a popular song of the day. The KR Shelbys also recieved a new-for-'68 428 Cobra Jet. Rather than the 428 Police Interceptor installed in other GT500's.
