Take the body of a solid-selling, midsized day driver -- the Buick Skylark -- and cram a monster of an engine in there. Then offer it in a well-publicized dual configuration -- it was available as either a convertible or a sedan, as was the trend -- and wait. While the Grand Sport debuted in 1965, the car didn't really seize national attention for a few years. The GSX of 1967 was a beefy Buick, but it wasn't until the 1970 launch, with its 7.5-liter engine and capability of 400 horsepower, that people really got interested.
The Stage 1 GSX performance package claimed a base 360 horsepower, but testers assured the public that -- depending on upgrades to valves, heads and camshaft -- it could top 400. Capable of the quarter-mile in 13.38 seconds, this car was famously offered in only two iconic colors, "Apollo White" and "Saturn Yellow."