Fuel Injection Pressure Regulator for Holley® Billet Fuel Pressure Regulators ar. EST, MON to FRI. Dominator EFI Billet Fuel Pressure Regulator. Billet Fuel Pressure Regulators are part of a complete line of fuel system products from Holley? . They are precision machined from 6061-T6 billet aluminum for strength and durability. They feature a black bright […]