The Chrysler A engine is a small-block V8 gasoline engine built by Chrysler with polyspherical combustion chambers. It was produced from 1956 until 1967, when it was replaced by the wedge-head LA engine, although the LA was in production alongside the A from 1964 - 1967. It is not related to the hemispherical-head Hemi engine of the 1950s. The A engine was first released in 1956 and was used exclusively in Plymouths until 1958 and in Chryslers and Dodges from 1959 on. The Desoto and Dodge 270/315/325 poly was not related to the Plymouth Polys, using the same bottom end as the Dodge and Desoto Red Ram Hemi, but utilizing similar head architecture. The cylinder bore center distance is , larger than the earlier Dodge-based poly engines. The A engine formed the design basis of its successor, the LA engine, evidenced in the many parts that interchange between the two engine families. Plymouth 277 The 277 "Hy-Fire" was the first A-block engine, produced for 1955 in the fall of 1954 and sharing almost nothing but the basic concepts with other engines built by Chrysler. Bore is and stroke is for a piston displacement of . It was replaced by the 301 in 1957, except for in low-priced Plaza models where it continued to be used during the 1957 model year. Power for the two-barrel version is ; this increased to for the four-barrel "Power Pack" version which also came equipped with dual exhausts. The Power Pack was also fitted to the Facel Vega FV3, of which 48 examples were built in 1956 and 1957. 301 The Plymouth 301 replaced the 277 in 1957 and kept that engine's stroke. Its piston displacement is , thanks to the larger bore. These dimensions are entirely different from the 1955 Chrysler 301. This engine was also installed in the 1957–1958 Facel Vega FV3B. 303 The 1956 Plymouth 303 displaces and uses the same connecting rods as the 277; the bore is and the stroke is . This engine was used in the following vehicles: 1956 Dodge Custom Royal (Canadian) 1956 Chrysler Windsor (Canadian) 1956 Plymouth Fury, with 4-barrel carburetor 1957 standard on all -wheelbase Dodges and Plymouths 313 A version of the A engine called the 313 was produced from 1957 to 1967 primarily for Canadian and export markets. This engine has a bore of and the common stroke, and was used in the