Corvette tuner names…go. Let’s see…you have Callaway and the RPO B2K and SuperNatural machines. You have Mallet and the wild late-model rides. And…well, for anything else, we’re going to have to go back to the days of cheap gas, wild horsepower claims and a man so gifted at building street monsters that the EPA cracked down on him. Because if there is ever a measurement for insanity when it comes to hopping up factory machines, a government crackdown has to be the ultimate yardstick. The name is Joel Rosen, the location was Baldwin Chevrolet and the group was Motion Performance. Combine those three with a new Chevrolet and a wallet full of cash and you would drive out of the dealership in a bona fide weapon that had a personal guarantee from Mr. Rosen himself, one that was never called upon. 
The face of the Baldwin-Motion Phase III GT Corvette is a bit…well, it’s difficult to not make a Datsun 240Z crack, but it sure looks like someone had some inspiration. The taillights echo Pontiac, the scoops behind the doors echo Mustangs, and everything else about the car screamed, “I f-ing dare you to try it.” Phase III GT Corvettes were the most expensive offerings from Baldwin-Motion, with one car known to cost $13,000 in the money of yesteryear. This meant that maybe ten were built, with only a couple known to still exist in any form. 
With it’s original 435-horse 427 powertrain, this Phase III GT would be at the milder end of the performance scale from a Motion Corvette. But that was the beauty of Baldwin-Motion: if you had the cash you could make some serious fun happen. 535-horse big-blocks, 4.88 gears and a Hone Overdrive…it was all about how much you wanted to stop the other guy on the block.
Two interesting articles written by Martyn L.Schorr.One on the Motion Phase III GT Corvette,from Vette The World’s Leading Corvette Enthusiast Publication April 1992 and second Corvette From Six To Stingray,a Marque Series Book.Worth the information give by the author.