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Holley Billet Adjustable Regulator


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Billet Adjustable Regulator
More than 10 available
Billet Adjustable Regulator
  • Carbureted Applications
  • Bypass Style
  • Adjustable 4.5-9PSI
  • 3/8" NPT Ports
  • Ships

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    12-841 - Holley Billet Fuel Pressure Regulators is rated 4.6 out of 5 by 7.
    Rated 5 out of 5 by from Holley billet fuel regulator 12-841 Chose this regulator to regulate the pressure coming from the in tank GPA-4, 255 LPH fuel pump to a Holley 950 HP carburetor. The output pressure easily adjusted to 6 psi and maintains it nicely without fluctuations using braided 3/8” inlet, outlet and return lines. The supplied mounting bracket attached without issue to the inner fender well. Would recommend using a return style regulator over the deadhead version anytime to keep the fuel circulating and cool to help with eliminating any vapor lock issues that have become a problem with the modern ethanol containing fuels.
    Date published: 2023-07-04
    Rated 5 out of 5 by from great part Fixed all my problems, hot rod runs great now. Part came fast.
    Date published: 2017-05-16
    Rated 5 out of 5 by from Looks and Works Great... Working Great so far. Easy to install...Billet looks real good
    Date published: 2015-06-22
    Rated 5 out of 5 by from Works great! Bought this bypass regulator for a V8 S10 so I can use the factory in tank fuel pump. Add a JEGS fuel pressure gauge any you're set. Deadhead style regulators are a lot cheaper but you will burn out your fuel pump. Spend the extra cash now and save some frustration later.
    Date published: 2014-11-01
    Rated 4 out of 5 by from Installation was a breeze I installed it on a work in progress so I haven’t actually ran it yet but so far i am very satisfied.
    Date published: 2018-01-19
    Rated 3 out of 5 by from Works good looks good. I used mine for a tbi to carb conversion using the stock in tank electric fuel pump as recommended by holley and I'm satisfied with it so far...
    Date published: 2014-11-02
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    Can this be used with a mechanical fuel pump?

    Asked by: Kurt
    The Holley 510-12-841 regulator will work with a mechanical fuel pump.
    Answered by: jshook
    Date published: 2023-03-22

    What size return line should be used ? I have a Holley Blue Top pump with 1/2 inch supply line, 425 HP single 750 cfm Holley carb. 5 gal. fuel cell in a footbrake bracket car.

    Asked by: Willies
    You will want to use at least a 3/8" hose for the return line.
    Answered by: Rusty B
    Date published: 2018-09-13

    Bought model 510-12-841 that's for low pressure/carb ... can the spring be replaced and use for high pressure FI fuel pump? I am switching to FI and hate to spend another $100 on another one.

    Asked by: Mikes72
    No, this is a different designed regulator, you will need a high pressure unit.
    Answered by: Rusty B
    Date published: 2018-07-09

    Will this work with the Holley Mighty Mite fuel pumps 

    Asked by: Cannon23
    This regulator could be used with the Mighty Mite pump line.
    Answered by: Jon Jegs Tech
    Date published: 2018-10-08

    Can this be used with Hy-Fuel Tight-Fit In-Tank Retrofit Kit? What the max inlet pressure?

    Asked by: Luke
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