Rear quarter-windows replaced the stock air extractors on '66 models, and a GT350 gas cap was standard. The '66 cars had a different style of rear traction bar, which mounted below the axle. All of the '66 cars had rear-exiting exhaust. Leftover '65 cars still had the 15-inch wheels, but the '66 versions came standard with a 14-inch Magnum 500 wheel. Shelby 10-spoke wheels in a diameter of 14 inches were available as an option, and some cars also came furnished with painted steel wheels. Also produced in '66 were 1001 special models made for Hertz car rental. These GT350s had chromed Magnum 500 wheels, and were usually black with gold trim. Most of the Hertz cars came with the C4 three-speed automatic transmission. However, some Hertz GT350 cars were equipped with four-speed transmissions. In April 1966, a Paxton supercharger became an available option.
The '67 Shelby GT500 seen here shows how different the car looks from the standard '67 Mus
In '67, the Mustang changed dramatically. Although the car looked similar to the '66, there were no interchangeable body panels. With the new and larger platform, the Mustang would now accept a bigger engine. Hence, the Shelby cars were no longer restricted to a 289ci displacement, and it didn't take long for Mr. Shelby to capitalize on the possibilities. For '67, the GT350 continued to be based on the K-code 289. While the Paxton supercharger was still offered as an option, the big news for the '67 Shelby was the introduction of the GT500. This car offered a warmed-up FE 428ci "Police Interceptor" engine. Equipped with dual four-barrel Holley carbs, the big engine was rated at 355 hp. Due to production difficulties, a few of the '67 GT500s reportedly got the 390ci engine. A handful of GT500s were made with the medium-riser 427ci engine. The exact number of the 427 cars made is not known, but an original 427-powered '67 GT500 would be a collector's dream come true.
The '68 Shelby GT500KR seen here shows the different front-end treatment, twin-scoop hood,
While the '65-'66 Shelbys were almost identical in appearance to the stock Mustang, the new Shelby cars looked very different from their Mustang brethren. A fiberglass extension was added to the nose of the car, making it look longer and lower. In fact, the good-looking addition added 3 inches to the overall length of the car. This required a special hood, which was made of fiberglass and equipped with a functional scoop. Hood retaining pins became standard equipment. Two large driving lights were mounted in the grille opening very near the centerline of the car. Some had the lights situated at the outer ends of the grille opening, depending on varying state laws. Out back, upper and lower scoops were furnished. Lower scoops were intended to function for rear-brake cooling, while the upper scoops were used in place of the now-ornamental sail-panel gratings found on the regular Mustang fastback. All of these body modifications gave the new Shelby an outrageous look that still turns heads today.
This is the engine that caused all of the fuss-the Cobra Jet 428. This notorious engine co
In 1968, Shelby production ended at the LAX location and was switched to the A.O. Smith Company in Livonia, Michigan. Ford brass felt that better control of the Shelby operation would be possible at the Michigan location. The '68 Shelby front end was restyled yet again, and with very nice results. The front end was again produced in fiberglass. The '68 cars were furnished with a twin-scoop fiberglass hood. The GT500 still came with the Police Interceptor 428. Again, a few of the GT500s came with the 427 engine, this time the low-riser version. For '68, the 427 could be had only with an automatic transmission. Some big news for the '68 GT500 came later in the year when the Cobra Jet version of the 428 became available. This engine replaced the Police 428, and the cars equipped with the Cobra Jet engine became known as the GT500KR. The KR suffix stood for "King of the Road," a moniker borrowed from a popular song of the time. The CJ 428 was rated at 335 hp, a very conservative figure, most likely provided to appease insurance companies. Most sources agree the Cobra Jet 428 cranked out around 400 streetable horsepower.