holley performance products is an automotive performance company based in bowling green, kentucky. holley, when based in michigan, was one of the major producers of carburetors, being supplied as standard equipment on many detroit-built automobiles. holley has supplied carburetors for everything from the original ford model a, world war ii airplanes, and the factory muscle cars of the 1960s. later they manufactured carburetors for both street and racing applications such as the holley double pumper and dominator. holley-style carburetors have powered every nascar sprint cup team and every nhra pro stock champion until both series eventually switched to electronic fuel injection. nascar sprint cup engines still utilize a holley throttle body and holley efi is the spec efi system in nhra pro stock. holley's product range has expanded to include the aforementioned fuel injection systems, performance fuel pumps, intake manifolds, superchargers, nitrous oxide injection, performance plumbing