With the initial success of the Gran Sport, Buick added several variants when the 1968 redesign occurred. Now available as the California Gran Sport, Gran Sport 350, Gran Sport 400, and eventually the Gran Sport 455, Buick had a GS for everyone. The top-of-the-line GSX offered more torque and standard equipment than any other muscle car of the era. But if you want to bring your GS into the modern era, we have everything you need to bolt a Gen III/IV LS between the framerails.

From Ford Flathead to GM Gen V LT, and including everything in between like small-block and big-block Ford and Chevy, Gen III/IV LS, Coyote, Hemi, and more, we have the parts to coax more power out of the engine under the hood of your hot rod.