In October of 1961, an American racing driver named Carroll Shelby approached AC Cars wanting to fit a 4.2 liter V8 Ford engine into the AC Ace chassis. AC Cars agreed and in March 1962, the first original Cobra was built. It was the first super-fast car. Not long after, they fitted a 4.7-litre engine, which boosted power from 165 to approximately 200 horsepower and gave it a new top speed of 140 miles per hour.
1964 saw an even larger engine fitted; Ford's famed 427 racing engine (7.0-litre) developing 485 brake horsepower and attaining a top speed of 163mph. Some Shelby Cobras were fitted with Ford's 428 engine, a less powerful engine despite the nominal increase in displacement, intended for road use rather than racing.
In addition, the Cobra is possibly the most cloned car in history; an astounding number of replica Cobras have been produced, to the extent that the originals are in a definite minority. Some are mere AC Cobra lookalikes, while others are perfect replicas in every detail.