Shelby GT500 Super Snake 427 Twin-Supercharged

Shelby GT500 Super Snake 427 Twin-Supercharged

The 1967 Shelby GT500 Super Snake is the Holy Grail of the Mustang world and one of the most legendary automobiles in all of automotive history. It is a singular creation — literally one of one — built as a promotional vehicle for the Goodyear Thunderbolt tire line and representing the most extreme expression of Carroll Shelby's philosophy of putting the biggest possible engine in the smallest possible car. The Super Snake is not merely rare; it is unique, and its story is one of the most fascinating in the annals of American muscle.

The Super Snake began life as a standard 1967 Shelby GT500, which itself was already a formidable machine powered by the 428 Police Interceptor V8. Carroll Shelby had the car sent back to his facility in Los Angeles where the 428 was removed and replaced with a 427 FE-series V8 engine — the same basic engine used in the Ford GT40 Mark II that had won Le Mans in 1966. But Shelby was not satisfied with a merely Le Mans-winning engine. He had the 427 fitted with twin Paxton centrifugal superchargers, creating a powertrain that produced an estimated 800 horsepower — an almost incomprehensible figure for 1967.

The twin Paxton supercharger setup was an engineering challenge even for Shelby's experienced team. The two centrifugal blowers were belt-driven from the engine's crankshaft and fed pressurized air through a custom intake manifold to the dual four-barrel Holley carburetors. The result was an engine that produced power on a scale that was almost unprecedented in a road-going vehicle. To handle this power, the car received a heavy-duty C-6 automatic transmission — no manual gearbox available at the time could reliably handle 800 horsepower.

The stated purpose of the Super Snake was to demonstrate the durability of Goodyear's Thunderbolt tires. Carroll Shelby personally drove the car at high speed around Goodyear's five-mile test track in San Angelo, Texas, reportedly averaging over 150 mph for an extended period with the car performing flawlessly. The demonstration proved that the Thunderbolt tires could withstand extreme speeds and heat, exactly as Goodyear intended.

Shelby initially planned to build approximately 50 Super Snake models for sale to the public, with a projected price of around $8,000 — roughly double the cost of a standard GT500. However, the immense cost of the twin-supercharged 427 engines and the complexity of the installation made the project economically unfeasible. The idea was abandoned, and the single prototype remained the only Super Snake ever built.

The car's subsequent history is as dramatic as its creation. After its promotional duties, the Super Snake passed through several owners over the decades. Its significance was recognized early, and it became perhaps the most sought-after Shelby Mustang in existence. When it finally came to auction in 2019 at Mecum's Kissimmee sale, the automotive world held its breath. The Super Snake sold for $2.2 million, confirming its status as one of the most valuable American muscle cars ever sold.

The Super Snake represents the absolute zenith of the 1960s muscle car philosophy taken to its logical extreme. Where other manufacturers were content with 400 or 450 horsepower, Carroll Shelby doubled down — literally — with twin superchargers and 800 horsepower. The car is a monument to an era when automotive regulations were minimal, safety concerns were an afterthought, and the only limit was the imagination and audacity of the builder. There will never be another car quite like the 1967 GT500 Super Snake, because there will never again be a combination of circumstances — the freedom, the technology, the sheer will to build something this outrageous — that could produce it.

For Shelby historians and Mustang collectors, the Super Snake exists in a realm beyond mere collectibility. It is an artifact of an era, a physical embodiment of Carroll Shelby's larger-than-life personality, and proof that sometimes the most important thing about a car is not how many were made, but how impossibly, gloriously excessive a single example can be.