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.

The GM LS engine has quickly become the high-performance standard in the performance aftermarket. Holley and Hooker have partnered together to offer the most versatile and complete LS swap kits on the market so you can install the GM LS engine into your favorite chassis! These swap kits have been engineered by Holley for a easy bolt-in engine swap where all the parts work together as a fully engineered system.