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In 1989 Callaway introduced a Speedster which was the culmination of their styling, engineering and trimming talents. Their first example was a bright green ZR1, which had a severely chopped windscreen, no side mirrors, eighteen inch wheels and a vibrant blue leather interior stitched purposefully from Germany. Nothing about Callaway’s Speedster was reserved, and this is especially true when investigating the specification. The car had 450 horsepower.
As early as the late 1990's, San Francisco based coach-builder SV Motor Company envisioned a car that took the raw performance of a Corvette and refined it with a touch of Italian flair.  Their vision was to infuse many of the design elements found in the Alfa Romeo 8C Competizione (from which the SV 9 clearly drew its inspiration, as well as its name) with a 2009 Chevy Corvette.
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).
The 2005-2013 Callaway Corvette was a specialist version of the C6 Corvette, built by Callaway Cars expert craftsmen and sold through selected Callaway/Chevrolet dealers. The 17th “C-Project” undertaken by Callaway first produced naturally-aspirated SuperNatural™ 450, 461, 490 (6.0L) and 550 (6.8L & 7.0L) horsepower Callaway Corvettes. In February 2006, Callaway returned to its positive manifold pressure roots, introducing Callaway “SuperCharged” Corvettes.
To understand why the Guldstrand GS-90 coupe and convertible differ so much, keep in mind that during the course of the C4 development cycle, no ZR-1 convertibles were planned, so the base C4 convertible had to be used in building a GS-90 Nassau Roadster, as it was called. The coupe, however, had the advantage of using the ZR-1 platform right from the get-go.
To commemorate its quarter-century milestone, Callaway Cars collaborated with Chevrolet, arranging a production run of 25 uniquely prepared 2012 Corvette Grand Sport coupes and convertibles. General Motors supplied special parts and procedures on the Bowling Green production line to facilitate final assembly at Callaway factories. Then, the performance and identity components are installed by Callaway. The 25th Anniversary Edition produced 620 bhp and 555 lb-ft of torque.