HP Billet Carbureted By-Pass Fuel Pressure Regulator

Street/Strip Carbureted Applications Two Port Adjustable from 4.5 to 9 PSI

PART# 12-841

Suggested Retail: $108.95
Your Price: $97.34
Free Shipping on orders over $100*


Holley® 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 dip anodized body and a clear bright dip anodized top for corrosion resistance and good looks. The Holley 12-841 fuel pressure regulator features 3/8" NPT in/out ports and a 3/8 NPT return port.


  • Adjustable from 4.5-9 psi for precise fuel pressure adjustments
  • Constructed of billet aluminum with a black anodized base and clear anodize top for good looks
  • Used in systems with a return line back to tank
  • Use with electric pumps only
  • One 3/8" NPT inlet, one 3/8" NPT outlet and one 3/8" NPT return (or bypass)
  • 1/8" NPT gauge port
  • Comparable and interchangeable with popular Holley® 12-803BP regulator
  • Mounting bracket included


ColorBlack Anodized
Emission Code3
Fuel SystemCarbureted
Fuel TypeGasoline / Diesel / E85
Inlet Size3/8 inch NPT
Outlet Size3/8 inch NPT
Pressure Range4.5-9 PSI
Product TypeRegulator
Return Size3/8 inch NPT
WarningCalifornia Proposition 65

Tech Resources


This part is legal for use on Uncontrolled (Non-Emissions Controlled) Vehicles or Racing Vehicles.

The following vehicles are considered Uncontrolled (Non-Emissions Controlled) Vehicles:

  • 1965 and older U.S. manufactured California Certified vehicles
  • 1967 and older U.S. manufactured Federally Certified vehicles
  • 1967 and older Foreign manufactured vehicle

Racing Vehicles are vehicles that are used exclusively for racing or other forms of competition that are not registered and that may never be used on the street.

WARNING FOR 12-841: This product contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.
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    *Free Shipping & Handling only offered to the continental US on orders over $100.

    Some parts are not legal for use in California or other states with similar regulations.