The Peterson pump-mounted vacuum regulator for Star Machine vacuum pumps is an adjustable regulator intended to control crankcase vacuum. It is offered as a pump-mounted unit and is described as capable of regulating vacuum across a wide range. The regulator fits a -12 port AN, includes an aluminum weld bung for the valve cover, and a retrofit kit is available to convert earlier regulator designs to the new configuration.
Peterson Fluid Systems Vacuum Regulator Pump Mounted