The mid-1970s wasn’t a great time for American fans of performance cars. Spiraling insurance costs, falling compression ratios to accommodate low-lead gas and heavy 5 mph bumpers all took their toll on the once great muscle car.

But not everyone went down without a fight. In 1973 Pontiac unveiled the epic Trans Am Super Duty, and Motion Performance built this incredible Manta Ray from a C3 Corvette. In fact, Motion built two other Manta Rays that year, shortly before the company closed its doors, but this is the only survivor and it’s getting ready to go under the hammer at Mecum’s Indy sale in May.

Motion Performance, like that other legendary muscle-tuning outfit, Yenko, took Detroit’s top-tier muscle cars and dialed them up to 11. Joel Rosen and his partner Marty Schorr set up shop next to Baldwin Chevrolet of Long Island in 1966, and over the next few years Baldwin-Motion produced a series of ultra high performance Novas, Camaros, Chevelles and Corvettes, even going so far as to guarantee the quarter mile performance of its most extreme creations.

Related: This C6 Corvette With A C3 Body Is The Perfect Combination Of Old And New

In the case of the Corvette, its plastic body allowed Baldwin-Motion to make some serious styling changes to match the performance increases, resulting in cars you already knew were going to massacre you at the stoplight long before that light had flicked from red to green.

The Manta Ray’s custom bodywork included a new nose that swapped the standard Vette’s pop-up lights for European-style integrated lamps, and a boat-tail rear with clear echoes of Bill Mitchell’s 1965 Mako Shark Corvette concept car. Together with a giant ducktail spoiler, those mods dramatically altered the look of the donor C3.

The two other Manta Rays were apparently fitted with 454-cu in big block V8s and four-speed transmissions, but this car’s original buyer clearly preferred show to go. He settled for a mellower 350-cube V8 and three-speed automatic, which might explain how it’s still in one piece almost 50 years later.

By the late 1980s the car was in poor shape and it ended up in the hands of a body shop owner who drove it around for several years without realizing what he had on his hands. Then an incredible chance meeting with the car’s creator, Joel Rosen, at a car show resulted in the long-lost 350 being replaced with a date-correct unit that Rosen helped build to 425 hp.

It’s difficult to value such a rare machine, but this same car last sold for $100,000 in 2016, which seems pretty reasonable considering its historical importance. Like it? Bookmark Mecum’s May sale and get bidding.

Hat tip to Silodrome