in 1964 the 442 stood for 4BBL, 4spd dual exhaust as the car only came with 4 speed manual. In 65 the 400ci V8 was introduced with auto trans option. During that year through 69 the 442 stood for 400 ciV8, 4BBl carb and dual exhaust. The 442 changed with introduction in 70 with the 455. Soon after the 442 was only an option package on the Cutlass models.