Chrysler built only 16 examples of a fuel-injected 392 Hemi for the 1958 300D, and 15 of them were quietly retrofitted back to carburetors within the same model year. That’s just one chapter in a decade where Chrysler’s FirePower Hemi and DeSoto’s own separate Hemi family kept leapfrogging each other in displacement and horsepower. Read on to find out how a 331-cubic-inch engine grew into some of the most powerful production V8s of the 1950s.