Overview The Holley VR Series billet fuel pressure regulators are part of the VR1 and VR2 Series brushless fuel systems product line. These regulators can support 3000+ horsepower engines that require high volumes of fuel flow. Both EFI and carbureted versions can be referenced on a 1:1 ratio. They are precision machined from 6061-T6 billet aluminum for strength and durability and feature a black bright dip anodized body and a clear bright dip anodized top for corrosion resistance and good looks. Offered in 2 port and 4 port versions for carbureted or EFI pressures, Holley has the regulator to cover your needs! Regulator is compatible with Diesel #1 and Diesel #2. Always use a fuel pressure gauge to monitor any changes during adjustment. Pictured is 12-851 showing similiar installation Features 4 port design Billet material Adjustable Return style 40-100 PSI pressure range (1) 10 AN and (4) 8 AN O-ring inlet/outlet size 10 AN O-ring return size 1/8" NPT gauge port with 1/8" NPT vaccum/boost reference port Designed for use with the Holley VR1 and VR2 Series Brushless in-line fuel pumps Compatible with gasoline, methanol, and E85 Includes a -4 AN fitting if being used in a boosted application TECHNICAL SPECS Pressure Range 40-100 PSI