Two were built. Carrol's own and one that was sold to Bill Cosby. Cosby was so scared of his that he sold it very quickly, and then it disappeared into the mist of history, supposedly driven off of a cliff into the Pacific..
427 big block with two superchargers.
https://www.roadandtrack.com/news/a35540420/shelby-427-cobra-super-snake-for-sale/
@Weezimp @Render @SalK IDK if that interview is still available on the Carson archives but I was watching it that night. Cosby had another story about how cool he felt in his Ferrari. He pulled into a gas station and said 'fill it up'. The attendant walked around the car and asked 'Where?". Cosby said 'I don't know...you're the mechanic...spray it all over the car maybe it will seep in...'