Carroll Shelby had already made a name for himself building the powerful cars like the 289 Cobra, but when the Cobra-Jet engine was developed, Shelby saw another opportunity—or, perhaps more appropriately, the opportunity. Shelby used the engine to create the GT500 “KR”—“King of the Road.”
To keep the insurance companies happy, and to keep the competition at bay, the Cobra-Jet 428 engine was listed at 335 horsepower. The truth, however, was that the engine was capable of at least 400 horsepower with 440 lb-ft of torque. Improvements over the old Police Interceptor engine included low-riser heads and a bigger crank, rods, pistons, and exhaust manifolds.
Bigger tires and changes to the suspension helped the GT500 KR to handle better than essentially all of its competition. The Cobra-Jet engine was mated to a four-speed manual transmission. With a top speed of 140 miles per hour, the Cobra could hit 0 to 100 in 6.5 seconds.
But it wasn’t just the engine that set the KR apart. Larger vents were placed above the front grille. The rear was widened out and outfitted with Thunderbird taillights. Shelby also added in twist-lock hood pins, chrome bumpers, and a twin-exhaust layout. The car also featured “Cobra Jet 428” emblems on the fenders and gas cap, “GT500 KR” graphics on the front fenders, and Shelby’s iconic stripes on the side skirt.
The KR drove so well, that rivals backed down just at the sight of the King of the Road.