All engines have an additional prefix preceding the 480 to indicate the specific configuration of the engine. Although the series is known as the "O-480", there are only geared engines in the series. There are also numerous engine suffixes, denoting different accessories such as different manufacturers' carburetors, or different magnetos.
Normally aspirated Opposed engine, equipped with a carburetor and Gearbox at the front end of the crankshaft to drive the propeller fewer revolutions per minute than the engine.
Supercharger driven by the engine, gearbox to drive propeller, and equipped with a carburetor. Designated the O-480-1 by the US military.
Supercharger driven by the engine, gearbox to drive propeller, with fuel Injection. Designated the O-480-3 by the US military.
Gearbox to drive propeller, normally aspirated with fuel injection.