As avid readers of this periodic column know, I eagerly devote its pages to the examination of the world’s most rare and valuable muscle cars.
So scarce are the cars we have examined in the past, that not one of them had more than 1500 examples produced. In fact, many prior subjects, such as the 1969 Chevrolet Corvette Stingray ZL1 and the 1970 Dodge Coronet R/T Hemi convertible, had production numbers in the single digits.
With figures like that, one might assume that those cars represent the absolute rarest of the rare. They are indeed amongst them. However, if you really want to enter a discussion about the true muscle car unicorn, then you need look no further than the 1967 Shelby GT500 Super Snake, the rarest muscle car in the world, and the focus of this edition of Rare Rides!
The Shelby Mustang came into existence as a result of Ford vice-president Lee Iacocca’s need to fulfill the promise he had made at the Mustang launch in April of 1964: that the Mustang would be a high-performance vehicle, capable of both street use and racing. In actuality, the first-generation car lacked chops both in terms of power and handling to qualify as anything more than just a spirited pony car. Iacocca thus sought an outside contractor that could modify the car and make it an honest competition vehicle.
Carroll Shelby, having had a long association with Ford which included using the company’s lumps in his Cobra sportscars, and helping to develop the GT40 race car that later went on to beat Ferrari at Le Mans in 1966, was the obvious person for Iacocca to turn to.
“So, Lee, you want me to make a racehorse out of a mule?” Shelby joked after Iacocca laid out his vision for a high-performance Mustang. Nonetheless, a deal was struck, and in August of 1964, the first 110 Mustang Fastbacks arrived at the Shelby American facility on Princeton Street in Venice, California to be worked on.
The basic Shelby Mustang, given the random moniker “GT350” for the number of feet between the race and production shops at Shelby American, was blessed with a 289 cubic-inch K-Code V8 engine which bumped the Mustang’s horsepower to an underrated 306 ponies by virtue of a Holley four-barrel 750cfm carburetor, Cobra Hi-Rise manifold, cast-aluminum valve covers and oil sump, a larger radiator and tubular Tri-Y exhaust headers feeding short side pipes.
Other mechanical upgrades included a quick-ratio steering rack, oil coolers for the differential, semi-elliptical leaf springs, a beefier rear axle from the Ford Galaxie, more robust anti-roll bars, Koni adjustable shock absorbers, Kelsey-Hayes front disc brakes, and a trunk-mounted battery for better weight distribution.
A four-speed, Borg-Warner T10 all-synchro transmission with close ratios housed in an aluminum case and tailshaft, and a ratchet-type limited-slip differential were standard equipment.
The cars featured a number of exterior modifications as well, which included a fiberglass hood with functional scoop and hold-down pins, an open grille, and 15-inch Kelsey-Hayes mag wheels shod with Goodyear high-performance Blue Dot tires.
The car was only offered in Wimbledon White with Guardsman Blue rocker panel stipes with call-out. Roughly thirty percent of the cars that left the Shelby garage came outfitted with the matching Le Mans style racing stripes across the top.
Inside, the GT350 had its rear seat deleted, and featured a new instrument cluster with a revised tachometer.
For those who craved an even higher echelon of performance, a GT350R model was also produced for 1965, which complied with SCCA racing specifications out of the box and was, therefore, ready to race. Horsepower was upped to 360, thanks to heavily modified heads.
Considerable attention was paid to weight savings in the Rs which included the removal of the heater, defroster, sound insulation, upholstery, headliner, and rear quarter windows, and vents. Lightweight seats, a stripped instrument panel, plastic windows, a roll cage, and a unique fiberglass front apron completed the package.
The Shelby GT350 made its public debut on January 27, 1965. In total, only 562 GT350s were built that year with 34 of those being R-spec cars.
1966 was largely a continuation year for the GT350, with changes being limited to several new colors, functional brake scoops on the flanks, new rear-quarter windows, and extended exhaust pipes to reduce noise in the cabin. A few consumer-friendly options such as an optional SelectShift 3-speed slushbox and fold-down rear seats were offered.
Additionally, the famous Shelby GT350H models were built specially for Hertz Rental Cars in 1966, featuring a unique black and gold color scheme. Wanna-be racers could then trash someone else’s Shelby for a weekend at their favorite track.
1967, however, was hardly a carryover year. Ford had completely restyled the Mustang, making it both larger and heavier. Carroll Shelby took this as an opportunity to do what he originally wanted to do with the ’65-’66 cars, and make the Shelby’s aesthetics markedly distinct from their lesser Mustang brethren.
To that end, Shelby outfitted the ’67 GT350 cars with bespoke fiberglass body pieces, including a gorgeous elongated nose, a hood with twin functional scoops, and four body side intakes located at the quarter windows and along the car’s flanks ahead of the rear wheels. A fiberglass tail featured an integrated spoiler and sequential turn-signal/tail lamps pilfered from the Mercury Cougar. Twin, round high-beam headlights were mounted in the center of the grille (they were later located in the grille corners to comply with differing state laws.)
More than just giving the Shelby Mustangs a unique appearance, the changes to the front end of the car allowed for a big-block engine to be fitted. This marked the genesis of a second Shelby Mustang model, the legendary GT500.
Mechanically, the GT500 was a significantly different beast from its GT350 stablemate. Shoehorned into the engine bay was an FE-series 428 cubic-inch Police Interceptor V8. Usually reserved for bigger Ford vehicles in which it put out 345 ponies, Shelby outfitted the motor with twin 600-cfm Holley four-barrel carbs atop a cast-aluminum medium-rise intake manifold raided from Ford’s 427. Output was a sarcastically underrated 355 brake horsepower and 420 lb-ft of twist.
Mated to this lump was a choice of a RUGS-1 four-speed manual transmission with limited-slip differential or a three-speed auto. Rear-axle ratios ranged from 3.50:1 to 4.11:1.
Stiffer springs front and rear, a larger anti-roll bar, and Gabriel adjustable shocks all around differentiated the GT500 from a standard Mustang GT. The GT500 also featured front disc brakes with fade-resistant organic friction material as standard equipment along with drums in the rear. A choice of three different 15” wheels was offered, all fitted with Goodyear E70-I5s.
Inside, the GT500 received an upgraded dash with a 140 mph speedo and 8000 rpm tach, and an ammeter and oil pressure gauge located in the center. Shelby badges were present on the wood-rimmed steering wheel and dash, while a backseat and full roll cage – the first ever fitted in an American production car – were standard.
Externally the GT350 and GT500 looked identical, save for the call-outs on the rocker stripes.
The performance was heady for 1967, with the GT500 able to do 0-60 in six seconds, and cover the quarter-mile in 14.6 seconds at 99 mph.
Sales for the GT500 were good, outselling the GT350 in the first year. Impressed by the car, Don McCain, a salesman at Mel Burns Ford in Long Beach, California, thought there could be a market for a more extreme version of the GT500.
McCain suggested to Carroll Shelby that he drop in the raucous Ford 427 cubic-inch V8, which was roughly 70 horsepower more powerful than the 428 Police Interceptor engine that came standard.
Shelby liked the idea, in part because, as Goodyear’s West Coast distributor, Shelby American had been contracted to run a public relations test for the brand’s latest tire, the Thunderbolt. Shelby saw a hyper-performance Mustang as an ideal vehicle to test the tire.
In typical Carroll Shelby style, he took McCain’s idea of using the 427 one step further, asking his chief engineer, Fred Goodell, to use a 520 horsepower racing-spec 427 from the GT40 Mk II program instead.
Goodell randomly chose a white GT500 for the build, serial number 67402F4A00544, to be the prototype GT500 “Super Snake,” a name reportedly thought up by Don McCain. The 428 was dropped and replaced with a medium riser Mark II 427 with aluminum heads, forged cam, Le Mans spec-rods, a single 780 cfm Holley carb, and a special set of “bundle of snakes” headers.
To complement this monster of a powerplant, Goodell added an external oil cooler, braided lines, a remote oil filter, a Detroit Locker rear end with a set of tall 2.73 rear gears, heavy-duty front disc brakes, traction bars, and a redesigned grille for additional cooling.
Custom, Guardsman Blue triple Le Mans stripes were applied over the Wimbledon White paint, and a set of Shelby 10-spoke wheels were mounted, of course, with a set of 7.75”x15” whitewall Goodyear Thunderbolts.
In March of 1967, the Super Snake was brought to Goodyear’s five-mile-long oval test track in San Angelo, Texas. Carroll Shelby personally treated the editors of Time and Life Magazines to 170 mph terror rides, before handing the keys over to Goodell, who piloted the car to an average speed of 142 mph for 500 miles. Post-run, the Thunderbolts, which had been overinflated with nitrogen to keep the sidewalls from overheating, were found to still have 97 percent of their tread.
Afterward, the car was shipped to Mel Burns Ford and put on display to drum up sales. Sadly, the demand just wasn’t there, largely in part to the Super Snake’s price tag, which at $8,000, was almost double the price of a standard GT500, and $1000 more than a 427 Cobra.
Ultimately, the lone Super Snake was sold to a pair of Braniff Airlines pilots in Dallas, Texas who installed 4.10:1 gears and drag raced the car for a period of time.
The Super Snake subsequently changed hands a number of times over the years, until most recently being sold at Mecum’s 2019 auction in Kissimmee, Florida. There it fetched $2.2 million, making it the third most valuable Mustang in history after the $3.84 million paid for the prototype 1965 Shelby GT350R raced by Ken Miles and $3.74 million collected for the 1968 Mustang GT from the movie Bullitt.
Somehow, that price doesn’t seem exorbitant for the world’s rarest ride…