There is sort of a romantic notion that every muscle car in the Golden Age had either a 426 Hemi, 428 Super Cobra Jet, or 454 ...
Straight off the bat, it's the engine sizes. The Mopar 383 V8 displaces 383 cubic inches (6.3 liters), sitting between the 340 (5.6 liters) and 440 (7.2 liters). The 340, 383, and 440 all are part of ...