"Combining the power of Ford's short-stroke V8 with the nibleness of AC's sporting chassis, the Cobra was the first largely successful English-American hybrid. The whole project was motivated by legendary driver Carol Shelby, who refined and raced the car with funds from Ford.
In what some have called a desperate move, AC Cars accepted a deal to modify their Ace chassis to accept Ford's V8 engine. They shipped bare chassis to Shelby American where they were initially fitted Ford's 260 cu in. engine. The V8 worked well within the spacious engine bay, so much so, Shelby moved to the 289 unit in 1964, and the massive 427 with a new, stronger chassis in 1965.
Since development was relatively simple, the Cobra started winning races from its onset. It had a tremendously good power to weight ratio that bettered with both the 289 and 427 engines. In a short time, the Cobra built up an impressive racing record and a purposeful 427 Coupe won the GT Championship in 1964 and placed fourth at Le Mans in the same year.
Due to the early success of the Cobra, Ford was happy to continue development of their engines and pursue new interests. This lead to GT40, a super low racecar developed in both Britain and USA that upset Ferrari's dominance in a major way.
The definitive version of the Cobra (and some would argue the Ace as well) was the Cobra 427 S/C. These were full-on competition spec cars that were unable to race due to homologation problems. Shelby sold around 30 of these cars which became America's most capable and expensive road-going cars."
