2014 Shelby GT500

The "basic" GT350 dialed up the Mustang's output by 35 hp, up to 306 hp, courtesy of a 289 CID K-Code engine, while also offering modified steering, a functional hood scoop and 15-inch wheels wearing low-angle Goodyear tires. A beefier rear axle from the Ford Galaxie was standard, as were Koni adjustable shock absorbers and Kelsey-Hayes front disc brakes. The early cars were also a little hard to drive, with a clutch that could be described as heavy. The GT350R dialed up the output even further, up to 360 hp, but only 34 examples of this model were made.

For the 1966 model year the Shelby Mustang lineup gained a new model: the GT350H "Rent-A-Racers" finished in black with gold stripes.

"Ford supplied the new Mustangs with V8 engines and mostly automatic transmissions, Shelby added extra performance and style and Hertz gave the public access to a unique driving experience through what was known then as its new 'Rent-A-Racer' program," Ford said.

1,001 examples of the GT350H were produced for Hertz, and of course were later acquired by enthusiasts. The ones that weren't wrecked by car renters, anyway.

The GT500 that debuted for 1967 was a different beast from those earlier models.

For one thing, it was powered by a 428 CID engine with two 600-CFM Holley carburetors, rated at 355 hp and 420 lb-ft of torque, paired with a choice of a four-speed manual or a three-speed automatic. The engine itself also featured a cast aluminum intake manifold. Actually, there were two engine options for the GT500 for 1967 -- the other was Ford's 427 CID V8 that was quite a bit more expensive than the Shelby-modified 428 CID unit.

One would think that 355 hp and 420 lb-ft of torque would be enough to satisfy all customers seeking a faster Mustang, but halfway through 1968 Shelby offered the GT500KR, which stood for "King of the Road."

Powered by the new 428 CID Cobra Jet V8 engine with a single 735-CFM Holley four-barrel carburetor with a ram air system, this engine received an upgraded camshaft, reworked cylinder heads and connecting rods and an upgraded crankshaft. The output, at least officially, was still 355, but in reality it was well over the 400-hp mark.

The reign of the original GT500 cars was not long: Shelby's relationship with Ford began to fray by 1969, as Shelby sought to move on to personal projects. 1969 was really the final year for the first-generation versions of the Shelby GT500, even though several hundred unsold examples from that year were later reworked by Ford into 1970 model year cars. And for a long time, Shelby and Ford closed the book on the GT500 nameplate.

Only decades later, Ford brought back the GT500 nameplate in 2005 with the model entering production two years later.
(Source: Autoweek.com)