The Gran Sport name has been used on several high-performance cars built by Buick since 1965. In the GM brands hierarchy, Buick was surpassed in luxury and comfort appointments only by Cadillac, which did not produce performance models. As a result, the Buick GS series were the most opulently equipped GM sport models of their era. The Gran Sport performance enhancements on all Buick products during this era sought to affirm Buick's tradition of producing powerful and comfortable products going back to the 1930s when all Buicks of the time were upgraded to the Buick Fireball Straight Eight, then installed the 278 cu in (4.6 L) Roadmaster engine in the shortest model Special and introduced the Century, known as "the banker's hot rod" with a three speed syncromesh manual transmission. The Gran Sport sought to identify cars that were fun to drive with a luxury approach.
Gran Sport 340/350
In 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 lb·ft (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.
