The Buick Gran Sport GSX was a variant of the Buick Gran Sport that was introduced for the 1970 model year, the Gran Sport GSX, more often referred to as simply GSX, was initially offered as a package on the GS455 in 1970, but for 1971 and 1972, it was available on any Gran Sport, although fewer overall were sold. These well-equipped, high-performance muscle cars were available in a range of combinations during the course of production, with a 350ci or 455ci V8 for the last two years it was built. Notably, GSX cars were also available with the Stage 1 performance package. Production of the Buick Gran Sport GSX ended in 1972.