The 383 was Chrysler's volume B-engine — RB's smaller sibling, sharing block architecture with the 350/361/400 but with a unique bore/stroke. 4.25-inch bore, 3.375-inch stroke. Cast-iron block, polysphere combustion chambers (later upgraded). Production 1959–1971 across passenger cars + light trucks.
Two muscle-car variants: the L-code 2-bbl economy 383 (rated 290 horsepower 1968–70 gross) and the N-code 4-bbl Magnum (rated 335–340 horsepower depending on year). The Magnum was the standard engine on B-body performance cars (Coronet R/T, Charger R/T, Road Runner, Super Bee) where the 440 wasn't ordered. SALES codes: E63 covers the 2-bbl; E64 covers the 4-bbl Magnum (some references conflate these — Plenum tracks E64 specifically).
Final year was 1971 — the 383 was dropped for 1972 in favor of the 400 cid B-engine, which used a larger bore and revised emissions tuning to meet the new federal regs. The 1971 383 Magnum is therefore the apex Mopar 4-bbl 383.