The Mopar 400 Big Block engine for Chrysler, Dodge and Plymouth makes is a member of the B-series of V-8 engines. This series included with 350, 361 and 383 cubic inch displacements. The 400-cubic inch engine was introduced in 1972 in a high-performance and a standard version. This engine was essentially a bored-out version of the 383 engine and was introduced in response to new smog control legislation. By 1978, B-series V-8 engine production halted.

1972 400 Engine Specifications

The 1972 400 V-8 engine came with a choice of a two-barrel carburetor (standard variant) and a four-barrel carburetor (high performance variant). Both variations had the same engine block, which had a bore and stroke of 4.34 inches by 3.38 inches. The compression ratio of both variations was 8.2-to-1 and the normal oil pressure was between 45 and 65 psi.