Which V8 engine name powered the 1949 Oldsmobile 88?

The 1949 Oldsmobile 88 was powered by the Rocket V8.

Oldsmobile introduced the 88 as a lighter, mid-range car fitted with the company’s new 303-cubic-inch overhead-valve V8. The engine had been developed for the larger Oldsmobile 98, but placing it in the smaller 88 body produced an unusually strong power-to-weight combination for the period.

The 1949 Rocket V8 used a 90-degree layout, overhead valves, and high compression. Its published output was 135 horsepower and 263 lb-ft of torque. The engine’s performance helped make the 88 a sensation, and the car became a prominent early competitor in NASCAR and the Carrera Panamericana.

“Rocket” is the engine family’s popular name, while Oldsmobile V8 is the broader technical designation. The alternatives in the question belong to other manufacturers or engine families: Ford used Y-block terminology, Buick is associated with the Nailhead, and Chrysler used the FirePower name.