
Unveiling the Legend of Zora Arkus-Duntov’s 163 MPH Corvette Prototype: The 1954/1955 EX87 Corvette Test Mule
The Extraordinary Journey of an American Icon
The Chevrolet Corvette, an iconic symbol of American muscle, speed, and innovation, owes much of its legendary status to a pivotal moment in the mid-1950s. This is when Zora Arkus-Duntov, the visionary Chief Engineer of the Corvette, pushed the boundaries of automotive engineering with the 1954/1955 EX87 test mule. During a daring run at the Arizona Proving Grounds, Arkus-Duntov achieved an astounding speed of 163 mph, setting the stage for the Corvette’s legacy as a high-performance sports car. Join us as we delve into the captivating story of the 1954/1955 EX87 and the man who transformed it into an automotive legend.


EX87 Corvette Test Mule Specifications
- Engine: Originally: 265 C.I V8; Currently: 307 C.I. V8
- Horsepower: 280
- Transmission: 3-speed manual
- Weight: 2800 lbs
- Top Speed: 163 mph
In this article:
- Zora Arkus-Duntov: Chief Engineer for the Corvette
- The Transformative Modifications: EX87 Corvette Test Mule
- Pushing the Limits in Arizona and Daytona
- Legacy and Impact
- Conclusion
- Description
- Photos of EX87 Corvette Test Mule on display at the Eyes on Design 2022
- Here are some other articles you might enjoy:
Zora Arkus-Duntov: Chief Engineer for the Corvette
Before we delve into the fascinating tale of the 1954/1955 EX87 test mule, it’s imperative to understand the driving force behind this project—Zora Arkus-Duntov. Born in Belgium in 1909, Arkus-Duntov was a brilliant engineer and avid car enthusiast who migrated to the United States in 1930. In 1953, he joined General Motors (GM), swiftly ascending to the position of Chief Engineer for the Corvette project.
Arkus-Duntov possessed a vision for the Corvette that transcended its original concept as a stylish roadster. He envisioned the Corvette as a high-performance sports car capable of competing with the world’s best. To breathe life into his vision, he needed a platform to experiment and push the Corvette’s limits. That’s where the 1954/1955 EX87 test mule enters the picture.
The Transformative Modifications: EX87 Corvette Test Mule
The 1954/1955 EX87 test mule began its journey as a modified 1954 Corvette—an integral part of the development process. Arkus-Duntov and his GM Engineering Staff team in Detroit transformed this vehicle into a high-speed test platform, implementing various modifications to enhance its performance.
Engine Upgrades:
In the mid-1950s, Arkus-Duntov collaborated with the legendary Smokey Yunick to install an experimental V8 engine into the 1954 Corvette test mule. This bold move significantly augmented the car’s power and performance.
Windshield and Aerodynamics:
To reduce drag and improve aerodynamics, Arkus-Duntov replaced the windshield with a curved Plexiglas windscreen. Additionally, he added a fiberglass tonneau cover over the passenger side of the cockpit, enhancing aerodynamic efficiency.
High-Speed Stability:
Acknowledging the necessity of high-speed stability, Zora fabricated a fiberglass headrest-tailfin. This distinctive addition not only contributed to the car’s visual appeal but also enhanced stability during high-speed runs.
Zora then focused on the engine, increasing its displacement from 283 to 307 cubic inches and procuring a special camshaft from GM’s Engineering department. Once these modifications were complete, EX87 received a new tracking number—5951—and returned to Zora at Chevrolet Engineering to prepare for a high-speed record attempt at Daytona Beach in January 1956.
Pushing the Limits in Arizona and Daytona
With these extensive modifications in place, Zora Arkus-Duntov took the 1954/1955 EX87 test mule to GM’s Arizona Desert Proving Ground. The Engineering team delivered the specially ordered “Duntov Cam” to the proving grounds, which, once installed, enabled the test mule to set a new record of 163 miles per hour. The “Duntov Cam” itself became legendary in the automotive world.
Legacy and Impact
The record-breaking runs of the 1954/1955 EX87 test mule at the Arizona Proving Grounds and Daytona Beach had a profound impact on the Corvette’s development. They showcased the Corvette’s potential as a high-performance sports car and solidified Zora Arkus-Duntov’s legacy as the visionary who transformed it. The Corvette ceased to be merely a stylish roadster—it became a high-speed powerhouse, laying the foundation for decades of American automotive excellence.
Conclusion
The tale of the 1954/1955 EX87 test mule, its historical significance, and Zora Arkus-Duntov’s audacious experiments remain pivotal moments in Chevrolet Corvette’s history. It epitomizes the relentless pursuit of excellence and innovation that has characterized the Corvette for generations. This legendary test mule, with its daring modifications and record-breaking speed, stands as a testament to the vision and determination of one man, Zora Arkus-Duntov, who transformed the Corvette from a stylish car into an enduring symbol of American performance and speed.
At Dana Mecum’s Original 22nd Spring Classic Auction in May 2009, the Duntov Test Mule EX-87 Corvette sold for $318,000 (from the Bob McDorman Collection) to automotive collector and renowned Corvette enthusiast Ken Lingenfelter.
After Ken Lingenfelter, owner of Lingenfelter Performance Engineering in Brighton, Michigan, purchased the Corvette, with assistance from Christo Datini, the lead archivist for the GM Media Archive, he unearthed valuable documents at the General Motors Heritage Center. These documents shed light on the car’s history and evolution, further enhancing our understanding of this iconic vehicle.
After resting in Yunick’s garage for 46 years, the experimental engine and cam were finally reunited with EX-87 and its GM log book in 2003, marking a significant moment in history as the very first Corvette to be equipped with a small block V8 engine.
Description
- Zora Arkus-Duntov’s testing car
- Known to be the world’s first V8-powered Corvette
- Prototype “Duntov Cam” was used in its 265 C.I. V8 engine
- The engine’s displacement was increased to 307 C.I.
- Numerous body modifications for speed runs, including a tail fin
- Driven to 163 mph in 1955 by Smokey Yunick at the GM Arizona Proving Grounds
- The experimental engine was reunited with the car in 2003 after nearly 50 years of separation
Photos of EX87 Corvette Test Mule on display at the Eyes on Design 2022



This Corvette made history as the first V8-powered model in the Corvette lineup, thanks to the pioneering work of Mauri Rose, Chevrolet’s Chief Engineer, who introduced a groundbreaking 265 cu in V8 engine into the EX-87. Later, Zora Arkus-Duntov took the reins, aiming to enhance performance and set speed records. With his guidance, the engine grew to 307 cubic inches, featuring a prototype “Duntov cam” and achieving remarkable high performance. In 1955, Smokey Yunick drove the car to a record-setting speed of 163 MPH at GM Proving Grounds.
The car’s distinctive elements, including the unique wraparound windshield, passenger seat ‘tonneau cover,’ and tail fin, all emerged from Duntov’s inventive mind, enhancing stability at high speeds.
While not a racer, this test mule logged countless hours and miles, reflecting Duntov’s relentless pursuit of automotive excellence.
Notably, captivating photos taken at the Eyes on Design event in 2022 by Wayne Ellwood provide valuable insights into the EX-87 test mule’s remarkable history.
Explore Vette Vues Magazine Subscriptions, the ultimate choice for Corvette enthusiasts. Enjoy 52 years of rich history and in-depth insights into all things Corvette. From the classic C1 to the cutting-edge C8, each monthly issue is packed with features, reviews, restoration tips, event highlights, racing updates, auction results, model cars, classifieds, premium products, and more. Discover the latest Corvette news and uncover fascinating historical facts. Subscribe now!
For those eager to continue their Corvette adventures, our Corvette event calendar is your gateway to a world of thrilling experiences with your Vette. Discover more exciting events, gatherings, and celebrations that will fuel your passion for these iconic American sports cars. Join us in exploring the road ahead and uncover your next unforgettable Corvette adventure on our Event calendar. Your journey of speed, style, and camaraderie awaits!
Stay updated with our newsletter for regular updates and exciting features; you can sign up here for free. Plus, don’t forget to explore our online store, where you’ll find a fantastic selection of Corvette books, t-shirts, hats/caps, bags, and coolers adorned with Corvette logos. By subscribing and shopping with us, you not only stay plugged into the Corvette community but also support the rich heritage of these legendary vehicles. Join us in celebrating all things Corvette!
Here are some other articles you might enjoy:
1953 EX-122 Corvette – The Corvette that Inspired Zora
Unveiling the Unique 1966 ‘Tanker’ Corvette: The 427 Version
1960 Camoradi Corvette Le Mans Racer, Bid to $1,100,000 But Did Not Sell