Fast Lane Flashback
The 1965 - 1970 Shelby GT350 & GT500 Mustangs
By: Lawren Dame \ Associate Editor \ July 14, 2014
The Shelby Mustang—a name so familiar and renowned that it rolls off the tongue almost as easily as it rolls down the road, certainly one of the most enduring visions of muscle and power ever built.
It wasn’t always this way, however. In the mid-1960s the Mustang was not quite up to par with its possibilities. By the summer of 1964 it was decently successful, with its first high-performance engine, a 271 horsepower 289 cubic inch V-8; however, Ford had the vision to transform the Mustang into a vehicle with strength and prowess—a true muscle car. It was then that Ford Motor Company enlisted the aid of the racecar genius, Carroll Shelby, to lead such a task.
Shelby’s skilled track testing determined that the Mustang lacked quicker steering, better brakes, and—most importantly of all—horsepower. The result: the 1965 Ford Mustang Shelby GT350. This vehicle was as the closest thing to a street-legal racecar, with modified high-performance suspension, a lighter fiberglass hood with air scoops, fast-ratio steering, larger disc brakes, and engine improvements that boosted the horsepower from the factory’s 271 to 306 horsepower.
The backseat was removed and replaced with room for a spare tire and fiberglass cover, which allowed the GT350 to be qualified as a sports car rather than a racecar—though the inside boasted racing seat belts and full instrumentation. The car was fitted with Koni adjustable shocks as well as larger sway bars in the front and back, 15 inch silver wheels, and a Detroit Locking rear complete with traction bar brackets. Only one transmission was available; the Borg Warner T-10 4-speed manual.
As for the Mustang’s appearance, it received side-exit exhaust pipes, a brand new paint job with a white body and blue stripes racing up and down its hood and sides, and Glasspack mufflers to aid sound enhancement. Though its horsepower was high, the Mustang was smaller and lighter than most of the muscle cars that occupied Detroit’s streets, and therefore was elevated to a level of its own. Unlike any other muscle car before it, the Shelby Mustang GT350 was one that could without a doubt handle well.
By 1966, the GT350 had lost its Mustang label and was instead simply known as the Shelby GT350, though in appearance it was nearly identical to the previous year’s model. The paint job, previously exclusively white, now included blue, red, green, or black, all with white stripes. The engine blocks experienced a color change as well; Mustang engine blocks were now painted a dark blue as opposed to the previous year’s black. Factory extractor vents were replaced by Plexiglas rear quarter-panel windows. A SelectShift 3-speed automatic was now available, as well as a Paxon supercharger, which boosted horsepower to numbers in excess of 400. Over-rider traction bars were no longer used, and the battery was no longer relocated to the trunk.
During this year, Shelby and the Hertz Corporation made a deal to produce a special line of rental car GT350s that would be refurbished and sold to the populace after serving as rentals. Hertz was given exclusive ownership of 1,000 such cars. These cars would be dubbed as GT350-H models, and the first models were white with blue stripes, much like the original 1965 GT350s. The remaining majority came with black paint and gold Le Mans stripes, with a black interior. These Hertz models wore chrome Magnum 500 wheels, and most received auto transmission. Of the Hertz cars, the first 85 were produced with a four-speed manual transmission and advertised as “Rent-a-Racer” cars, and were even sometimes used at Sports Car Club of America (SCCA) events as production class cars.
Additionally, there were a total of 1,373 fastbacks produced in 1966, including 252 early production model GT350s which originated as 1965 Mustang K-Code Fastbacks
The refreshed 1967 Ford Mustang was a larger and heavier breed to work with offering a 289-cubic-inch V-8 and an optional 390-cubic-inch V8 from the factory. Shelby shoehorned in a 428-cubic-inch V8 which generated 400 horsepower, although it was still marketed as 355 hp to pacify insurance companies. This new creation of American muscle was named the GT500.
As for the GT350, it kept its 289-cubic-inch V8 engine, but was forced to lose its original power-enhancing steel-tube exhaust headers due to newer noise regulations. Though the horsepower for the GT350 remained advertised at 306, in reality, it pushed 290 hp.
In terms of appearance, the Shelby Mustang underwent quite a few upgrades, from a custom fiberglass front fascia and two additional headlights in the grille’s center, to a multitude of functional scoops, covering the hood, sides of the lower body, and behind the windows. The interior of the Mustang was either black or parchment, outlined with either a two-point or four-point roll bar. The chassis could now handle more sharply, and racing-style modifications were installed in the interior, including a new steering wheel, extra gauges, and built-in inertia-reel shoulder harnesses. The trunk lid of this Mustang received a functional air spoiler, flanked by wide taillight clusters barrowed from the 1967 Mercury Cougar, minus the chrome trim. Each 1967 Shelby GT350 and GT500 came with rocker panel stripes and emblems on the front grille, fender, and rear deck. Each contained a pop-open gas cap with a Shelby Cobra cover as well. The car was updated with completely new power steering and brakes for this year, as previous models were similar to racecars and therefore had no need for power accessories.