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As the story goes, when the Corvette ZR-1 came out in 1990, Dick Guldstrand saw an opportunity to create his vision of the perfect Grand Sport ride, instead of his name just getting slapped onto another Chevrolet product. He asked GM for fifteen ZR-1’s and some money. He got one car and permission to do whatever he wanted to do with it. And that’s exactly what he did. Called the "GS90", Dick's car would prove to be the most elaborate and expensive specialty Corvette ever built.
Chevrolet's introduction of the LT1 in 1992 as the base engine in the Corvette phased out the L98 based Callaway Twin Turbo. Previously, Callaway Corvettes made their increased power through positive manifold pressure; now they made it through increased displacement and finesse. Initially called the CL1 or CR1, they designated the chassis they were built upon. They were based on the pushrod LT1 cars (CL1) or the 32 valve DOHC LT5 ZR-1 cars (CR1).
1969 Baldwin Motion Corvette
Various upgrade packages were offered by Motion Industries, for the Chevrolet models included within the Baldwin Corvette partnership. The most prominent of these packages included the SS (425 HP) and Phase III (500+ HP) offerings. These cars not only came with a performance promise, but a guarantee to back it up. All Phase III cars came with a personal guarantee.
Reeves Callaway has always had a dream of competing a Corvette of his own at the 24 Hours of Le Mans, France. The idea begin with the body work for a street version, but one thing led to another, and a full race version was completed as well. The street version is almost identical to the race version because the hood, tail, rocker panels, and lower door halves, are all made of carbon fiber, just like the race version.
The Zagato company took a C7 Corvette Z06 and transformed it into the IsoRivolta GTZ, a "spiritual descendant" of the Iso Grifo A3/C (Corsa).  The original A3/C race car was developed by Giotto Bizzarrini not long after he left Ferrari, where he had served as cheif engineer behind the 250 GTO, which is revered as the world's most expensive car.  Bizzarrini purportedly fancied the A3/C as his "own personal evolution of (and improvement upon) the GTO design."
When one of his cars was severely damaged in 1972, John Greenwood converted his 1969 L88 Convertible into a formidable race car. Included as the formidable ZL1 engine with 750 bhp on tap. Other modifications included a rear spoiler, quick replacement radiator and camber adjusters. At Le Mans, this car set the GT-class record for top speed down the Le Mans straight with 215 mph.