The Chevrolet "big-block" engine is a term for a series of large-displacement, naturally-aspirated, 90°, overhead valve, gasoline-powered, V8 engines; that were developed and produced by the Chevrolet Division of General Motors, from the 1950s until present. Chevrolet had introduced its popular small-block V8 in 1955, but needed something larger to power its medium duty trucks and the heavier cars that were on the drawing board. The big-block, which debuted in 1958 at 348 cu in (5.7 L), was built in standard displacements up to 496 cu in (8.1 L), with aftermarket crate engines sold by Chevrolet exceeding 500 cu in (8.2 L).