The Chrysler B and RB engines are a series of big-block V8 gasoline engines introduced in 1958 to replace the Chrysler FirePower engines. The B and RB engines are often referred to as "wedge" engines because they use wedge-shaped combustion chambers; this differentiates them from Chrysler's 426 Hemi big block engines that are typically referred to as "Hemi" or "426 Hemi" due to their hemispherical shaped combustion chambers. The corporation had been seeking a smaller and lighter replacement for its FirePower engines, in part because new styling dictates meant moving the engine forward in the chassis which negatively affected weight distribution.

The Chrysler Hemi engines, known by the trademark Hemi or HEMI, are a series of American V8 gasoline engines built by Chrysler with overhead valve hemispherical combustion chambers. Three different types of Hemi engines have been built by Chrysler for automobiles: the first from 1951 to 1958, the second from 1964 to 1971, and the third from 2003 to 2024. Although Chrysler is most identified with the use of "Hemi" as a marketing term, many other auto manufacturers have incorporated similar designs. The engine block and cylinder heads were cast and manufactured at Indianapolis Foundry.