Carroll Shelby had built a dual supercharged 427 Cobra (CSX3015) in 1967, which he pulled from one of the 19 MKIII Competitions. The Cobra was renamed "Super Snake" and in 1968, Road & Track referred to it as "The Cobra to End All Cobras."
In 1966, the MKIII Cobras were still being produced and raced. The MK III missed homologation for the 1965 season, but private owners continued to race the car and were winning races all the way into the 70s.
At the end of 1962, AC's chief engineer completed a major redesign of the car's front end and was able to fit it with rack and pinion steering. The new car entered production early 1963 and was designated MKII.
AC, a British specialty manufacturer was rumored to soon go bankrupt, and needed an engine to replace their dated pre-World War II design by BMW. Carroll Shelby airmailed AC a letter asking them if they would build him a car modified to accept a V8 engine.
The 1970 Shelby Mustang would be the last year from Shelby. Around 789 1969 Shelbys went unsold, so they were updated with new VINs under FBI supervision, and twin black hood stripes were added along with a Boss 302 type chin spoiler.
Shelby introduced a new model in 1967, the GT500. The GT350 continued to house the 289ci, while the GT500 received the larger 428ci. Shelby now began parting ways from the basic Mustang model to make the cars look more performance-oriented, while also being able to deliver that performance.