The Super Snake Story
No question about it, Shelby Mustangs bring top dollar in today's collector marketplace. They're coveted due to their special appearance, low production, and performance heritage. But stir in a special 427 engine along with documentation, including a Goodyear promotional video, that it was driven by Carroll Shelby at a tire test, and you're looking at the cream of the collector crop.
According to the Shelby American Automobile Club, Carroll Shelby asked Shelby American chief engineer Fred Goodell to install a GT40 Mk II 427 engine, with aluminum heads and solid lifters, in a '67 G.T. 500 for a tire test on Goodyear's five-mile banked oval in San Angelo, Texas. With members of the press invited, including Time and Life magazines, Carroll made the trip as well, driving members of the media around the track at speeds up to 150 mph. During the actual testing of Goodyear's new Thunderbolt tires, the Shelby set a record by averaging 142 mph for a continuous 500 miles.
With its test duty completed, Goodell searched for a buyer, eventually reaching out to former Shelby American field sales representative Don McCain, who had moved to performance dealer Mel Burns Ford in California. McCain recognized the opportunity to offer a unique 427-powered G.T. 500 through the Mel Burns dealership, similar to high-performance Chevy offerings from Yenko and Mr. Norm on the east coast, and suggested a run of 50 cars. However, when it was determined that such a car, even with a detuned 427, would retail in 427 Cobra territory at $7,500, McCain's idea was shelved.
http://www.mustangandfords.com/events/1309-million-dollar-mustangs-at-mecums-spring-classic-auction/