Holley was founded in 1903 by George M. Holley in the United States, at the dawn of the automobile industry. The company began building carburetors and quickly became a key supplier to early automakers, including Ford, whose Model T used Holley carburetion. Over the following decades Holley grew into one of the most recognized names in American fuel-system engineering.

Holley is best known for its 4150 and 4160 series four-barrel carburetors, which powered a huge share of American muscle cars from the 1950s through the 1970s, along with the high-performance Dominator carburetor used in racing applications. Today the company, based in Bowling Green, Kentucky, also produces electronic fuel injection systems such as Sniper and Terminator, along with fuel pumps and ignition components for street and racing engines.

The manuals available here cover the practical work involved in keeping Holley-equipped engines running properly. This includes carburetor rebuilding and jetting, float and needle adjustment, tuning procedures for different driving conditions, and step-by-step guidance for installing and configuring electronic fuel injection systems. Electrical wiring for EFI setups and basic diagnostic steps are also addressed, giving a complete picture of fuel-system service.

These manuals are intended for DIY owners restoring classic muscle cars, independent repair shops servicing carbureted engines, and enthusiasts upgrading to modern EFI. Whether rebuilding a decades-old 4150 carburetor or wiring in a new Sniper system, the manuals give clear factory-style instructions for getting the fuel system right.