By 1968, the Ford Mustang had already gained iconic status, being a popular choice among U.S. sports car enthusiasts due to its lightweight design, powerful drivetrains, and aggressive looks. The arrival of the Shelby GT350 in 1965 gave Ford even more credence on the performance market. The Shelbys became increasingly powerful over the years, but that didn’t stop Ford and Carroll Shelby to develop larger and more potent mills. In April 1968, a brand-new version of the 428-cubic-inch (7.0-liter) Police Interceptor V8 engine, with improved breathing heads and larger exhaust manifolds, was launched. Dropped into the range-topping Shelby GT500, the new engine gave birth to the Cobra GT500 KR.

GT500 KR was at the time the pinnacle of the Mustang’s evolution from both Carrol Shelby’s and Ford’s standpoint. The 1968 428 Police Interceptor FE big-block on the option list featured front Super Cobra Jet Engines, disc brakes and a functional ram-air scoop. Upon this foundation, Shelby went to work to create the iconic Shelby Mustang 500 KR.

Customers who demanded a KR ‘King of the Road’ Cobra could only settle for Shelby’s Mustang and it’s many improvements, such as, a redesigned fiberglass front end, hood design and rear end featuring 1967 Cougar taillights.

Interior customizations by Shelby only included a functional roll bar and a wood-rimmed steering wheel.

Ford underrated the 428 Cobra Jet at 335-horsepower, but in reality, it was more like: 400-horsepower and 440 pounds-feet of torque. The KR model was offered with a modified suspension and in fastback body configuration. Ford dealers sold 1,570 GT500KR models in 1968, 1053 fastbacks and 517 convertibles.

428-4V v8 engine 400hp (338hp for insurance purposes) @5200rpm Built in Metuchen NJ. Number built 1251 In 1967 at the New York Auto Show, Ford introduced the most powerful Shelby Mustang ever. Adding the ‘Cobra’ to Shelby’s moniker to help usher in the beginning of a new performance era at the company, Ford hit gold. The new 428 Cobra Jet V-8 was the powerhouse firmly planted under the KR’s custom fiberglass hood. This engine that once again launched the Mustang to the head of the pack.

The “KR” nameplate stood for “King of the Road,” which suggested that this was the most powerful Mustang ever built as of 1968. According to various sources, the Shelby GT500 KR got its name before the car was ever designed/slated to be built. Allegedly, Carroll Shelby got wind that Chevrolet was planning on trademarking the name “King of the Road”, so he got on the phone with his lawyer immediately and had him trademark the name before the folks over at Chevy could.

FoMoCo dropped the GT500 KR after ’68, right before Shelby stopped modifying Mustangs, ending production at a little over 1,200 units. Today, the King of the Road is regarded as the ultimate Shelby Mustang ever produced and it’s among the most expensive muscle cars when it hits the auction block.

Engine-aside, the King of the Road was recognizable due to its unique styling. The big vents atop the front grille were highlighted by Lucas or Marchal fog lamps, while the Ford Thunderbird-sourced taillights gave it a wide stance at the rear. Other notable features included twist-lock hood pins, chrome bumpers, a twin-exhaust layout, contrasting Shelby stripes above the side skirts, and “Cobra Jet 428” emblems on the fenders and gas cap, as well as “GT500 KR” graphics on the front fenders.

Inside, the KR had a Cobra-badged steering wheel, striped gear shift knob, and Cobra-embossed leather besides the usual GT500 equipment. Granted, the KR was rather subtle inside and out, but its special abilities became evident once the ignition key was turned and the accelerator pedal hit the floor.

The last of its kind…

Due to Ford and Shelby parting ways in 1969, the GT500 KR was dropped from the lineup, and even though FoMoCo continued to offer performance-oriented ‘Stang such as the Mach 1 or Boss 351, the King of the Road’s greatness was never equaled. What’s more, the 1973 oil crisis put an end to the Mustang as a muscle car, being replaced by a more compact and frugal vehicle starting 1974. The GT500 KR was revived in 2008 with styling cues from the original car, but even though it made for a successful tribute car, it will take some time until it becomes a classic.