Holley Ultra XP experience or stories anyone?

Fuel and Air Systems

  1. 1966post

    1966post Active Member

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    Looking a Holley Ultra XP for my 470. It's built pretty stout
    Anyone have an experience with the Holley Ultra XP carbs?


    Thanks
     
  2. 91r/t

    91r/t FBBO Gold Member FBBO Gold Member

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    I hear they have an adjustable air bleed built into the main body in the center to adjust air supply at idle with big cams. That's an awesome feature to have for sure!
     
  3. 1966post

    1966post Active Member

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    It sure is. Thank you!
     
  4. Trey

    Trey Active Member

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    I may have an outlier, but here's my news:
    Bought my 950 ultra xp from local dealer, who also dynoed the engine. He has serious chops- really knows these carbs. Mine had serious hole in the fuel curve under light, low speed rev- so bad i now have noise in the 5 speed trans. We tried one from another 500" motor and was better. The Smaller ultra, 850 I think wasn't much better. Carb goes back to holley, nobody knows what they did but it works. Also, the bowls on three that we looked at had terrible casting flaws on the bowls, caused gasket leaks. I filed them down and new gaskets.
     
  5. Trey

    Trey Active Member

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    ....if the electric pump overcomes my vapor issue, and have no further hiccups -that carb will be plenty good.
     
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