A One-of-Two 1957 Chevrolet Corvette SS XP-64 Comes Up For Sale

“Win on Sunday, Sell on Monday” was a commonly heard thing when it comes to racing, and in the 1950s through 1980s America, it pretty much worked exactly like that. Win a race over the weekend in a car that is somewhat connected to one available in a showroom, and sales would boost almost overnight! That notion is something Zora Arkus Duntov, nicknamed the “Father of the Corvette” for very obvious reasons, picked up on as well. In the late 1950s, he hatched a plan to take the Corvette racing, with this fabulous Corvette SS XP-64 as the result! But it wasn’t meant to be, as the project was canned after just one race. Nevertheless, it became a legend in its own right, and now one of only two ever built can be yours!

Along with perhaps the Ford Mustang (although technically a Muscle Car) and the Shelby Cobra, the Corvette is probably the most prolific American sports car ever to be put on the road. The reason for the Corvette’s creation lies in the fact that soldiers returning from Europe after WWII, were bringing over compact European sports cars from the likes of MG, Healey, Alfa Romeo and so on. GM’s Head of Styling Section, Harley Earl, recognized the commercial potential and green-lit the construction of a compact 2-seater under the codename Project Opel (After carmaker Opel, owned by GM at the time) at some point in the early 1950s. The result was the EX-122 prototype, which made its public debut at the 1953 General Motors Motorama in New York and entered production later that same year.

Although the curvy fibreglass body was brand new and quite revolutionary for Chevrolet, the selected brand to put it to market, the Corvette used mostly off-the-shelf GM components in an effort to keep prices down. Originally, it was fitted with a 235 cubic inch (3.85-litre) inline six-cylinder engine producing around 150 horsepower, which was fed through a two-speed Powerglide automatic transmission. Initial reviews weren’t very positive though, as the car was deemed underpowered and sluggish, despite the sporty looks. The small block V8 certainly made an impact by improving its sportscar-like image, but sales weren’t booming. Through small tweaks here and there, the first-gen Corvette (known as the C1) was updated almost on a yearly basis, before its C2 replacement made its appearance in 1962.

By then the car had gained popularity, and sales were on the rise. The C2 generation is mostly known for the 1963 Split-Window Corvette, which had two rear windows broken up by a ‘spine’ running from nose to tail. Produced for only one year, it remains one of the most sought-after models. Others include high-performance ZR-1, ZL1 or Z06 designated versions, produced over various generations. Despite regular upgrades and evolutions, the Corvette had always remained a front-engine two-seater sports car, until the C8 generation was introduced in 2020. It has also gained a reputation for being a performance bargain, offering power and speed comparable to Europe’s finest sports cars, yet at a considerably lower price. The C8 generation, introduced in 2020, moved the engine to the back and is available with various levels of performance. The top-spec C8 Corvette is the ZR1, fitted with a 5.5-litre twin-turbocharged V8 producing a monstrous 1,064bhp!

Duntov’s Corvette legacy

Now that we’ve covered the basics in over 70 years of Corvette history, let’s look at Zora Arkus Duntov’s impact on what’s affectionately known as “America’s Sports Car”. Duntov was born in 1909 in Brussels, Belgium, to a Jewish Russian mother and father. The family moved around a couple of times and settled in Berlin, Germany in 1927. There he met his wife, which he married in 1939, and shortly thereafter he joined the French Air Force. When France surrendered to Germany in 1942, Duntov and his wife, along with several other family members, fled to the USA and settled in Manhattan, New York.

From a young age, Duntov loved cars and motorcycles, and he and his brother would set up a stamping company in the US, machining parts for aircraft and ammunition to benefit the war efforts. After WWII was over, the two would switch to manufacturing aftermarket car parts, including cylinder heads for Ford engines. The company grew to be quite an established name, but financial turmoil thanks to a third business partner forced the Duntov brothers to close shop. Zora Arkus Duntov also pursued a racing career, participating in the Le Mans 24 Hours from 1952 to 1955, with a class win in 1954 and 1955 with a Porsche 550 RS Spyder.

Duntov joined General Motors in 1953, after he wrote a letter to Ed Cole, Chief Engineer for Chevrolet at the time, stating that while the new Corvette looked stunning, he wasn’t impressed by the engineering underneath. In fact, he added a technical paper on how the car could be improved, which ended up landing him a job as an Assistant Staff Engineer at GM. Shortly after joining the company, he laid out the plans to his superiors on how to improve the brand’s success and performance, primarily in the racing programs. By 1957, he had worked his way up to Director of High-Performance Vehicles at Chevrolet, which was about the time when the Corvette SS XP-64 came into the picture.

The Corvette SS XP-64

Built in 1957, the Corvette SS XP-64 was Duntov’s vision and personal project of what a proper racing Corvette. The car had been used in racing before, but primarily in production-based stock car form.  A year before the SS XP-64 would hit the track, Duntov campaigned and drove a series of stock and lightly modified Corvettes throughout 1956, proving the car’s capabilities in pretty much every race it entered. The SS XP-64 however, would turn things on their head, as it was the first purpose-built GM racecar, made possible by Duntov, Cole and Earl. GM’s intentions were to take the car to Le Mans, and use other races as proving ground and shakedown events in preparation for the legendary endurance race in France. A Mercedes-Benz 300 SL was sourced to use as a starting point for the chassis, but eventually, a lightweight custom tubular chrome-molybdenum frame was built by Duntov’s and Earl’s team.

GM installed independent front suspension, with a De Dion rear suspension setup. The car received a drum brake system all around, with wheel-mounted brakes up front and inboard-mounted ones in the back, similar to the Mercedes-Benz W196R. The system used an unconventional dual vacuum system (one for the front, and one for the rear brakes) operated by a single pedal. It would prove to be an issue the drivers had to work around in the early days of the car’s racing career, causing locking if not used correctly.

Power came from a 283 cubic-inch (4.6-litre) Chevrolet small block V8 fitted with high-performance parts that would up the power and lower the weight. A number of experimental components were used, such as an aluminium water pump, radiator core and clutch housing, as well as a magnesium oil pan. It was also fitted with Chevrolet’s Ramjet fuel injection system, comparable to top European race cars at the time. The engine’s output was about 310bhp, which was fed through a four-speed close-ration gearbox and breathed through side-exit exhausts.

The Corvette SS XP-64 received a proper coachbuilt body in agreement with Harley Earl and Ed Cole. The initial body was constructed out of fibreglass, with the second body being made of lightweight (but highly flammable!) magnesium. The low-slung design features just a couple of Corvette references but was primarily designed to be as aerodynamic as possible. The toothed front grill and side coves were the most stand-out styling elements carried over from the production cars.

The rest is a rather classic case of form-follows-function, with a long swooping front section, a low-cut window that curves into the doors, an integrated streamlined rollbar to better guide airflow coming off the driver’s head, and a uniquely shaped rear end with six tail lights. The cockpit incorporates two seats, racing instruments, and a wooden steering wheel. The wheels were cast magnesium, with quick-change knockoff hubs and special racing tyres.

Both cars were brought to Sebring for the 1957 edition of the 12 Hours, with John Fitch and Piero Taruffi replacing Stirling Moss and Juan Manuel Fangio who initially signed up to drive it. Running the fibreglass car first, the duo clocked in reasonable times in practice. With Duntov insisting on driving the magnesium car as well, lap times dropped considerably! During the early stages of the race, overheating issues caused technical problems with the car, forcing it to retire after just 23 laps (out of what ended up as a 197-lap race for the winner, Juan Manual Fangio in a Maserati 450S). Shortly thereafter, the Automobile Manufacturers Association voted to ban all racing programs for its member companies, which included General Motors and thus Chevrolet. That rendered the promising Corvette SS XP-64 obsolete, and it never raced again.

A total of two cars were constructed, with three more chassis being built but never completed. The one that is now coming up for auction is the original magnesium-bodied car driven by Fitch and Taruffi. The car itself has undergone extensive restoration and is finished in period-correct blue and silver paint. It will come across the auction block in RM Sotheby’s Miami 2025 auction event, on Thursday, February 27th. The estimate is USD 5,000,000 to USD 7,000,000 which would easily make it the most expensive Corvette ever to be sold if it would hit even the low end of that.

For more information, please visit RMSothebys.com.

Editorial Note: The images and information used for this article are sourced from and used with permission of RM Sotheby’s unless stated otherwise.