picking a carb

Discussion in 'High Performance Modifications' started by arm2004, Apr 22, 2019.

  1. COPO

    COPO Veteran Member Lifetime Gold Member

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    I'm a Holley lover so my pick is a 750 cfm with secondary vacuum. My spare Holley (3310-2 750) which burns better than the orig 780. I did sell an almost new 600 Holley since it ran out of air/fuel at 5,000 rpm in my 70 Z28.
     
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  2. Z28zz383

    Z28zz383 Veteran Member

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  3. DesmoEd

    DesmoEd Veteran Member

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    Transmission and rear gear ratio are really needed to make an informed decision.

    On a stick car with good gearing I don't see much need for a vacuum secondary carb.

    There is a lot to be said about having a carb purpose built. When I had the sbc built for the vette in my signature my engine guy suggested having one built from Chuck Nuytten here in Dallas. His exact words were that it would run like a FI setup and he was right. Chuck purpose built a 750 DP for my specific engine combo and its absolutely flawless everywhere, from off idle to partial throttle to full hammer down the car runs so well and smooth. I just had it in a vette shop getting a 4 wheel alignment after going to manual steering and the shop manager asked me who built the engine and carb after he test drove it - its that good. Even with the 15 lb flywheel it will run clean down at 1800 rpm in 5th gear - its the best carb I have ever had as was well worth the money
     
  4. G72Zed

    G72Zed Veteran Member

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    X2^^ Great post and key points made DesmoEd. It's amazing the performance/efficiency and drive-ability that can be attained with a custom carb & tune if you have access to that shop/person.
     
  5. arm2004

    arm2004 Member

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    350 turbo trans with 3.42 rear gears is the setup. Have not decided on tires/ size yet.
    The car will be used to cruise around in no racing just ride around on nice days. Thanks for the help so far
     
  6. jeff swisher

    jeff swisher Veteran Member

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    I say Edelbrock 1405.
    But it would really benefit you if you learned how to take them apart and clean them and stick them back together they are one of the simplest carbs to work on besides a Motorcraft 2 barrel.
    You want reliability and worry free get the Motorcraft 2 barrel.

    But I must be the lucky one because I have Holley , Qjets and AFB carbs and the above mentioned 2 Barrels and none of them gave me any issues for more miles than most people keep their cars for.
    But they need driven often. You let something sit and dry out and 2 weeks later go out to start it and it runs different that is on you.
    When fuel dries out it leaves deposits eventually that stuff will bite you in the end.

    Fuel injection is better in that aspect.
    But injectors eventually varnish up when you do that.

    As far as FI being better than a carb it would depend on the FI system used.
    Back in the early 1990's I removed a lot of FI and feed back electronic carbs and converted the vehicles to good old fashioned carbs and distributors and EVERY one of them got better MPG and more power everywhere.

    Carbs I used then were original carter AFB or Quadrajets.

    The Quadrajet is not a difficult or tricky carb to tinker with. Just look at one aspect at a time.
    Cooking the perfect steak and all the steps you go through with that steak from the time you kill the animal it came off of is much more difficult.

    I have a Holley on one vehicle and an Edelbrock on another.
    I am not biased either way.
    Drive the car often,Change the fuel filters often keep good air filters on them and make sure they seal well and your carb will last a very long time.
     
  7. 1980RS

    1980RS Veteran Member

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    I bet you are going to laugh after I tell you my 350 pump gas engine ran out of rpm at 6700 with my homemade 1850 600 Holley VS.
     
  8. G72Zed

    G72Zed Veteran Member

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    To the OP, If geared well, and using a true dual plane without an open spacer or cut down center, look into the Holley 750 VS or one based on it from a good carb shop.

    It's amazing the impact the intake design will have on the carb CFM's choice/preference/booster's and overall performance based on setup. Dual plane vs single plane is a big sweep in what is needed.

    Last month I built 3 complete Holley 650HP's for the same Team (358 sbc rules) tuned all 3 on the same day/dyno/fuel. Open plenum.

    Made 570+ HP, pulled till 7,200 and moved 740 cfm with that 650HP, right at 1.3 cfm per HP, but it's still a 650. Seen the opposite, engine has a 750 and only uses/moves 600-640cfm.
    Some carb's work great, other's not as well, and the kicker is they measure & look the same.
     
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