Add to Favorite Sellers. 12-846KIT Holley EFI Billet Bypass Fuel Pressure Regulator Kit. 15-60 Psi – Fittings and Gauge Included. Die Cast Aluminum Construction. Adjustable from 15-60 psi for precise fuel pressure adjustments. Used in return style systems with a line back to the fuel tank. 8 AN O-ring Inlet, Outlet, and 6 AN O-ring Return Port. 1/8 NPT Gauge Port and Earl’s Fuel Pressure Gauge (100187ERL). Customer Service & Feedback. So we have a chance to make it right – we want your repeat business! Check out the official Holley Performance. For more great deals!!