The Buick Gran Sport or GS was a high-performance option package available on a number of Buick models, including the Riviera, Skylark, Century and Wildcat. A special version of one model was given the package's name as its model name.n 1967 Buick added a 340 cu in (5,572 cc) version, there was the GS 340 and the GS California sub-model, little more than the Skylark hardtop with new badging and trim, The 340 produced 260 hp (194 kW) and 365 ft·lbf (495 Nm), and less than 4,000 cars were sold. It was replaced the next year with the GS 350 and similar GS California; these used Buick's 350 cu in (5,735 cc) small-block engine. A California 2-door coupe appeared in 1969, total GS sales for the year, not counting the new California coupe, were 12,465 (4,933 GS 350s, 7,532 GS 400s). Sales of the GS 350 for 1970 climbed to 9,948; in addition, 10,148 455 cu in (7.5 l) 2-doors were built. The Gran Sport 350 outlived its big brothers, lasting until V8 Gran Sport production stopped in 1975, replaced by the Gran Sport 231.
