Buick’s muscle car, the Gran Sport, began as an option package on the 1965 Skylark. The Skylark Gran Sport included the biggest engine that GM would allow, a 400-cubic inch V8. The Buick Gran Sport became a model in its own right in 1967, and it included different options and trim levels. For the next few years, buyers could get the Gran Sport 340, 400, 455, or GSX. The latter was a high performance package that was optional for the 455 and designed to be on par with the GTO Judge and Olds 442 W-30. Track down one of Buick’s legendary Gran Sport models by searching at FossilCars.