1968 Shelby Mustang GT500 KR

With Ford's updated Mustang for 1967 and its revised body shell which included an engine bay capable of accommodating the 390 big-block engine, Shelby American took full advantage by installing the more powerful 428 Interceptor V-8 to create the GT500. With 360 horsepower, the GT500 was extremely quick, but more was needed to counter Chrysler's factory-backed Hemi cars and Chevrolet's big-block cars on the dragstrip.

At the suggestion of Hot Rod Editor Eric Dahlquist and with input from Rhode Island's Tasca Ford, Ford responded with the 428 Cobra Jet that featured stronger internals, low-riser 427 heads, larger valves and combustion chambers, a nodular crank, stronger connecting rods, dished pistons, high rise aluminum intake manifold, and a 735 CFM Holley double pump carburetor. In hopes of pleasing the insurance companies and manipulating the NHRA's Super Stock factoring system, the CJ engine was factory-rated at 335 horsepower. Ford showcased its new powerplant in 1968 at the Winternationals, where a six-car Cobra Jet assault was unleashed resulting in an all-CJ SS/E final round with Al Joniec taking the class win and beating Chrysler's Dave Wren for Super Stock Eliminator.

With the engine's potential proven, Shelby installed it in his Mustangs for 1968 creating the Cobra Jet-powered GT500 KR (King of the Road). The valve covers on the GT500 KR read 'Cobra Le Mans,' referencing the Cobra Jet's success over Ferrari at Le Mans in 1966 and 1967. The 'King of the Road' name was a jab at Chevrolet who was planning on introducing a special Corvette with the same name. After a quick search, Shelby found that 'King of the Road' had not yet been copyrighted. Decal makers at 3M were called in that very day to come up with GT500 KR striping. Photos were taken, papers filed, and thus was born the Shelby GT500 KR.

With the CJ's 440 foot-pounds of torque available from just 3,400 RPM, the Shelby Mustangs were properly modified to cope with the tremendous power, including a Ford Top Loader four-speed manual transmission (267 were equipped with this transmission) or a C6 3-speed automatic. There were larger hydraulic disc brakes in the front and larger drums at the rear, under-hood suspension bracing, and staggered rear shocks to prevent axle wind-up and wheel hop during heavy acceleration. The suspension was independent at the front with A-arms and coils springs, with a live rear axle with semi-elliptic leaf springs and staggered shock absorbers.

Exterior modifications included the scooped fiberglass hood that helped channel fresh air to the fuel-hungry intake passages. There were side scoops, stylized wheels, Shelby-specific logos and graphics, and special taillight design. The interior received wood applique to the dash, plush seating, and a factory roll bar. All 1968 Shelby Mustangs were equipped with power front disc brakes, power steering, and fold-down rear seats. Options included the GT Equipment Group, Interior Decor Group, tachometer and trip odometer, Visibility Group, Sports Deck rear seat, Tilt-Away steering column, and AM Radio (among others).

A total of 1,571 GT500 KRs were built for 1968 - the only year they were offered. Of those, 1,053 were fastbacks and 518 were convertibles. 299 had factory air conditioning. By this point in history, Shelby American had outgrown its facilities at Los Angeles Airport, so the company was divided into three entities, with road-car production placed under Shelby Automotive, Inc. in Livonia, Michigan, with assembly subcontracted to A.O. Smith in nearby Ionia.

by Daniel Vaughan | Aug 2020