51501 Fuel Pressure Regulator. 10AN Inlets / Standard Seat / EFI (25-90 PSID). FUELAB 515 Series Fuel Pressure Regulators are designed with performance and flexibility in mind. They accept port style and non-port style union fittings without interference. The 515 Series Fuel Pressure Regulator has a -6AN return port located on the bottom. Two -10AN […]