Chevrolet Corvette Callaway
Corvette received styling refinements for 1991 that included wrap-around front parking/cornering lamps, new side-panel louvers and a ZR-1 style convex rear fascia on all models. To help differentiate the look of the ZR-1, its center high-mounted stop lamp remained on the roof, while it was integrated into the rear fascia on both Coupe and Convertible.
In 1991 the only non-GM Corvette performance option that could be ordered as an RPO was the Callaway Twin Turbo package known as RPO B2K. Performed by Callaway Cars, the modifications added twin intercooled turbochargers, revised engine management and 150 horsepower, raising output to over 400.
Source: Chevrolet press and Mecum Auctions