In 1968, Shelby released a Road Version of their by now famous racer, the GT500.
The Shelby GT500 428 KR, had all the power of the racer, but with some refinements for driver comfort on the American roads. The interior of course was more luxury, and the suspension a little softer for that reason.
Although the creature comforts are there, the power is also there! Together the Shelby GT500KR forms a combination that came to be known as the King of the Road (hence the KR initials).
The vintage video below is from a Car and Track TV show of the day hosted by Bud Lindemann;