The ultimate C4 Corvette was grossly undervalued until recently. The 1990 to 1995 Corvette ZR-1 has long been undervalued. So much so there's a joke about people buying the ZR-1's engine and they ...

These estimates do not include title, registration fees, lien fees, or any other fees that may be imposed by a governmental agency in connection with the sale ... other Corvettes, a C4 and C7 ...

However, while the Sledgehammer was one of the wildest tuner-built versions in terms of straight-line performance, another less-famous C4 special continues to fascinate hardcore Corvette ...