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There were several successful attempts to build a convertible ZR-1, most of them by private people. The DR-1 was a GM prototype to test the structural integrity of the ZR-1 chassis when it would be topless. The car was built by American Sunroof Corporation (ASC) for Don Runkle, who was the vice-president of Advanced Engineering Staff, which explains the “DR-1” designation. It was a standard convertible transformed to ZR-1 specs.
The early C4's had their problems, what with the 1984 Cross-Fire Injection and its unusual 4+3 manual transmission. By the late 1980's, the fourth-generation Corvette had evolved into a more desirable automobile, thanks in part to the arrival of the ZR-1. 
The Centennial Edition came finished exclusively in a Carbon Flash Metallic finish with satin-black graphics. Special badging graphics signifying Chevrolet’s racing history, including an image of Louis Chevrolet on the B-pillars, were added as accents to the cars finish. The wheels were also finished in satin black. All models also received red brake calipers. The exterior color scheme of the Centennial Edition Corvette is reinforced inside the car.
1971 ZR2 Convertible
Finally in 1971, both the ZR1 and ZR2 packages were offered side by side as initially intended. The solid lifter, 350 cubic-inch LT-1 found under the hood of the ZR1 featured a ‘178’ high-performance camshaft and a 780 CFM Holley four-barrel carburetor, which resided atop a specialized aluminum intake. The LT-1 featured a reduced compression ratio of 9.0:1 for the 1971 production year, relative to 11.0:1 specified the year prior.
This vehicle pioneered the advantages of “Active Suspension” and had GTP Corvette race car technology. Built at the Bowling Green Plant, this vehicle was developed as a prototype for a limited edition run in the 1990 model year. Chevrolet ordered it to be built with a complex, high-tech active suspension that includes an Eaton hydraulic pump and Moog actuators. This car and the technology inside of it led to the Active Handling system GM released in 1996.