FAST XFI Fuel Injector Harnesses connect the XFI ECU to the fuel injectors. These harnesses are designed to aC - Commodate most common V8 engines from the Chevrolet Small Block to GM LS Series, Ford Small and Big Blocks as well as Windsor, Modular, FE configurations. FAST also has taken the intiative to help out customers with less common applications such as Buick V6, Modern Chrysler and even 4 cylinder applications. And, while we may not have a custom tailored injector harness that fits your needs, all of our harnesses can be re - pinned for custom firing orders and reterminated to aC - Commodate different injector connectors.