Car collectors, listen up if you love a good backstory! A super important piece of Corvette history is up for grabs right now, but not for long.

This clean 1955 Chevy Corvette rides the famous EX87 chassis – the very first Vette that General Motors ever stuffed a V8 engine into. The auction for this incredible General Motors (GM) test mule, which helped shape the future of America’s Sports Car, ends this coming Monday, May 19.

Chassis EX87 started its journey as an unsold 1954 model. GM engineer and three-time Indy 500 winner Mauri Rose, who actually headed up the team that created the original Chevy small-block V8, was the first to equip the car with V8 power. Afterward, the legendary Zora Arkus-Duntov, often called the “father of the Corvette,” took the EX87 chassis for extensive high-speed development work at GM’s Arizona Proving Grounds. Arkus-Duntov pushed this very car past 160 MPH, proving to GM that a V8 was absolutely the way forward for the Corvette to become a true performance machine.

Today, the 1955-specification bodywork currently on the car and the 327 cubic-inch, all-aluminum V8 under its hood are period-correct replacements, not the original experimental units. After GM had dedicated V8 Corvettes ready for production in 1956, they separated the original test body from EX87 and swapped its Duntov-tuned 307 V8 and manual transmission for a 265 V8 and a 2-speed automatic.

While the 327 came along later, the car’s chassis is the real deal: EX87, the one steeped in early V8 development history. It’s been under the care of the same owner for an impressive 57 years and comes with loads of documentation. The chassis even shows some tell-tale signs of its test-bed days, like a tow hook once used for mounting speed-measuring gear.

The successful V8 experiments with EX87 completely changed the Corvette’s path. If Rose and Arkus-Duntov hadn’t convinced GM’s decision-makers with this car, the Corvette might have faded into obscurity. Instead, this chassis helped ensure the Corvette got the muscle it needed to become a legend, paving the way for icons like the current ZR1.

With the Bring a Trailer auction for chassis EX87 wrapping up this Monday, May 19, someone’s about to own a true piece of Corvette history. Forget thinking of it as just another old sports car. This very chassis, EX87, convinced GM to commit to V8 power, a decision that cemented the Corvette’s legacy and gave it the muscle that still defines America’s Sports Car over seventy years later.