The Buick V8 is a family of V8 engines produced by the Buick division of General Motors between 1953 and 1981. The first version replaced the Buick straight-eight. Displacements vary from (for the division's unique all-aluminum early 1960s engine) to for its last big block in 1976. All are naturally aspirated OHV pushrod engines, except for an optional turbocharged version of the short-lived 215 used in the 1962-63 Oldsmobile Jetfire. Six displacements of the engine were used in two generations between 1953 and 1966, varying from to ; three displacements of standard cast-iron small blocks between 1964 and 1981, and and ; one of the aluminum blocks (1961-1963); and three big blocks between 1967 and 1976 and and . Some of these Buick V8s, such as the 350, 400, and 455, had the same displacements as those from other GM divisions, but were otherwise entirely different engines. Buick "Nailhead" V8 (first generation) Buick's first generation of V8 was offered from 1953 through 1956. It was an OHV pushrod engine like the then-new Oldsmobile "Rocket" V8. While it was officially called by Buick the "Fireball V8" it became known as the "Nailhead" by enthusiasts for the unusual vertical alignment of its small-sized valves, features that were the result of putting both intake and exhaust valves on the intake manifold side of the "pent-roof combustion chamber" used in this engine series. (Originally, it was known to hot rodders as the “nail valve” because the valves had long stems and small heads which made them look like nails.) To offset the smaller-sized valves ( for the intake and for the exhaust) and restrictive port diameters, the Nailhead V8 family used a camshaft with greater lift and duration. The small-diameter intake runners allowed these engines to develop high torque, with many exceeding 1 ft-lb/cu in, exceptional for the time. All of the nailhead designs have a bore spacing. The high torque nature of the engine was developed to provide adequate acceleration when mated to the Dynaflow transmission which favored smoothness above most other design and marketing objectives. Dynaflow's non-shifting design was demonstrably smoother than the rough shifting automatics then available, to include GM's Hydramatic, and the Powerglide unit used by Chevrolet. After the war, manual transmissions fell out of fashion over and automatic transmissions were more popular. 264 The produced in 1954 and 1955 was a direct replacement for the 263 straight-eight and the