How to Choose a Carb?

Discussion in 'The Club House' started by Trez, Dec 10, 2012.

  1. Trez

    Trez Well-Known Member

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    I know we have some mechanics here so I thought id ask; How do you know what carburetor to put on a motor?

    Ive been looking up some for my '73 Scout with 258 I-6, It has the complete Clifford 6=8 setup. Right now I have a Holley 470 truck avenger, I got it because it was suppose to be the "next best thing" to EFI. It said it was designed for 4 & 6 cyl. motors, but I have it tuned as low as I can, its still running rich, and my secondarys dont open...

    Ive read all sorts of carbs are used Holley 2-bbls, Webers, Motorcraft 2100, and theres conflict about the 470 I have, some people love them, but most say that "too much" and not necessary to have a 4-bbl...

    From what Ive read I need a carb with 300-390 CFM?

    :confused:
     

  2. John_Deer

    John_Deer New Member

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    Personally, with 6 cylinders the best carburetor is the one that came on it. If the engine can handle a little more fuel just change the jet. I have been through the experiences you mentioned in your post. By just changing the jets in a stock carburetor you can experiment without burning a hole in your wallet.
     
  3. Trez

    Trez Well-Known Member

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    I cant put the old one on... They came with a 1-bbl Carter.
    Mine has the Clifford intake with cam, headers.. I dont have the old intake or exhaust manifolds, Clifford doesnt even make a 1-bbl adapter for their intake..
     
  4. Trez

    Trez Well-Known Member

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  5. Trez

    Trez Well-Known Member

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    Does anybody know the "pros & cons" of the different carbs?

    Like why should I pick a Holley over a Weber or vice versa?
     
  6. danf_fl

    danf_fl Retired Supporter

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    Holley is/was the preferred brand (I have a 650cfm on my '68 Charger).

    When looking for parts or to have someone work on it is easier than Weber or Carter.
     
  7. levelcross

    levelcross New Member

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    You will have far more options for tuning your carb with a Holley than a Weber or Carter. The rich problem may be too much cam and not enough head work or compression to take advantage of the cam or lack of static timing and advance in the distributor. Straight 6's can be built to produce some high numbers of torque but the high RPM's to get the HP # up are usually futile as they make more power under 6500 RPM's.
     
  8. JSStryker

    JSStryker New Member

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    Last edited: Dec 12, 2012
  9. Trez

    Trez Well-Known Member

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    Im really wanting to know the differences between the types of carbs and the "why"

    Everybodys telling me whats "best" but not why.. I keep getting "just put x on" (weather its a Holley, Weber, etc) Ive heard Webers are good on in-lines a few times, but makes them so?