COMPETITION ADJUSTABLE FUEL PRESSURE REGULATOR – 3-PORT. The BLOX Racing Competition 3-Port adjustable FPRs are designed to offer high performance and reliability. Each FPR unit comes pre-assembled from BLOX and is guaranteed to offer consistency each time the engine is turned on. These billet aluminum units feature -6AN inlet and return ports in-line which offers more flexibility during installation, 1/8 NPT ports, are compatible with gasoline, diesel, methanol and ethanol. FPRs are designed to work with aftermarket fuel rails and are available in an assortment of color combinations. For fuel injector engines only. Will NOT work with direct injection engines. Will NOT work on engines with carburetors. Fittings / hoses or any other parts for plumbing are Not included. Will NOT work on Diesel / TBI or TDI Engines. Send us a message.