A couple decades ago, the “King of the Hill” C4 ZR-1 was the fastest and best handling Corvette ever. But Dick “Mr. Corvette” Guldstrand wanted to take it to even greater heights, and developed his GS-90 version.

He had tuner Doug Rippie raise the Lotus-designed, aluminum LT5‘s factory output from 405 to 475 hp. And also added coilovers, fatter tires, a rounder nose with exposed headlights, and a rear panel with a dozen taillights. Drawing inspiration from the ’63 Grand Sport, he painted it Nassau Blue with a white race stripe.

Only a half-dozen were produced before the then-new C5 stole the spotlight. This GS-90 is number two, now owned by Charlie Budenz, a longtime Corvette enthusiast and a docent at the Riverside International Museum. He still drives it on the street, while the remaining five GS-90s languish in museums. While small in number, the GS-90 stands out as a last hurrah for the C4, a pinnacle of Corvette customizing.