Help with picking out a carb for 5.9 magnum

Fuel and Air Systems

  1. Bankjug

    Bankjug New Member

    Messages:
    2
    Likes Received:
    0
    Joined:
    May 19, 2021
    Location:
    Medford, Oregon
    Local Time:
    7:40 AM
    I "think" I've picked out a good carb to use, but coming here to get second/more opinions just in case. I'm still learning as I go, so might need some patience! I'm going to be running:

    -360 magnum bored 30 over
    -9.5:1 compression I was told
    -Edelbrock Performance RPM heads
    -Edelbrock Performer RPM air-gap intake
    -TTI headers
    -3.23 gears
    -I don't remember the cam specs, but definitely not stock. Something about 224/226 with 114 centerline or something like that?
    -I'd use the cfm calculators, but I have no clue on my redline numbers. I've never had a tach in the car, so I've never known about my RPM. (I WILL be adding one with the new engine though)

    Mostly street use, with some strip sightings for sure. I'm thinking of going with the Holley 670 Street Avenger. First time buying a new carb for a new engine, so just want to make sure I don't make a mistake with me choice. Thanks in advance!
     
  2. pishta

    pishta I know I'm right....

    Messages:
    21,425
    Likes Received:
    10808
    Joined:
    Oct 13, 2004
    Location:
    Tustin, CA
    Local Time:
    7:40 AM
    AVS2 has been getting some good results. I never liked Holleys, Carters seemed to have better low end manners and smoother transitions. and they dont seem to stray from the initial tune.
     
    • Agree Agree x 2
    • Like Like x 1
    • xLURKxDOGx

      xLURKxDOGx "An angel fat, at satan's feast"

      Messages:
      4,342
      Likes Received:
      1673
      Joined:
      Dec 27, 2013
      Location:
      PHX
      Local Time:
      7:40 AM
      750VS will work nicely.
       
      • Agree Agree x 1
      • forphorty

        forphorty Well-Known Member

        Messages:
        790
        Likes Received:
        404
        Joined:
        Jan 19, 2006
        Local Time:
        9:40 AM
        Folks have had lots of problems with the 670 SA
         
        • Agree Agree x 1
        • Ricks70Duster340

          Ricks70Duster340 Child of the King FABO Gold Member

          Messages:
          640
          Likes Received:
          427
          Joined:
          Feb 8, 2021
          Location:
          Sisterdale, TX
          Local Time:
          9:40 AM
          I have both the 670 street avenger and the 650 AVS2. Both work very well, but the AVS2 has a bit better throttle response due to the newer booster design. I will say that my current 360 engine has a stock cam. I have heard that the AVS2 is a little more difficult to tune with a hotter cam. You will get opinions on both sides.
           
        • MOPAROFFICIAL

          MOPAROFFICIAL FABO Gold Member FABO Gold Member

          Messages:
          9,476
          Likes Received:
          8831
          Joined:
          Jun 1, 2016
          Location:
          Oceanside ca.
          Local Time:
          7:40 AM
          The problem is... its for stock engines,4x4s.
          Add some camshaft... and the thing is hicupping .
           
        • sireland67

          sireland67 FABO Gold Member FABO Gold Member

          Messages:
          9,716
          Likes Received:
          4078
          Joined:
          Oct 27, 2010
          Location:
          WV
          Local Time:
          10:40 AM
          625 street demon, most likely will work fine out of the box.
          Street avengers seem to always be lean out of the box, I have one and do not care for it.
           
        • mopowers

          mopowers Well-Known Member

          Messages:
          6,033
          Likes Received:
          3233
          Joined:
          Feb 15, 2006
          Location:
          West Sacramento, CA
          Local Time:
          7:40 AM
          My 340 hated the 670SA I tried on it. Only way to make it work would've been to drill and tap the IFRs and do some serious tuning. Completely doable, but not really what I wanted to do with a brand new carb. I sold it and picked up a 750DP and couldn't be happier.
           
        • 66fyssh

          66fyssh Don't Stop Believin' FABO Gold Member

          Messages:
          6,505
          Likes Received:
          6356
          Joined:
          Jun 22, 2013
          Location:
          Northwest GA
          Local Time:
          10:40 AM
          My build is similar. Stock bore 5.9 Magnum with new rings and bearings, Edelbrock 2.02 heads, Air Gap, Doug's headers. Cam is a Oregon Cam Grinding regrind of my core, .215/.223 @.050, .517 lift.

          I started with a Edelbrock 750. Thing pulled really strong, but it would dump gas occasionally for no reason and foul the plugs. Bought a brand new AVS 650 and it has very crisp throttle response but I feel like the engine wants more and ran stronger with the 750.

          I may rebuild the 750 and try it again. I like the simplicity of Edelbrock.

          Good luck, half the fun is in experimenting!!!
           
        • sireland67

          sireland67 FABO Gold Member FABO Gold Member

          Messages:
          9,716
          Likes Received:
          4078
          Joined:
          Oct 27, 2010
          Location:
          WV
          Local Time:
          10:40 AM
          i know the 625 street demon I had, is a very versitle carb.
          It worked good on a stock 318 with nothing more than LD4B intake and stock exhaust.
          Same carb I used on a 10.81 compression 5.9 mag with stock eldebrock heads, added headers and duel exhaust.
          Simple carb adjustments and it ran good, same truck 4X4 W150 4-speed.

          I liked the carb so much I bought another one for my 340 4-speed Duster, it cured the hot start issue I was having with the 700 Holley Double pumper.
           
          • Like Like x 1
          • Thanks! Thanks! x 1
          • MOPAROFFICIAL

            MOPAROFFICIAL FABO Gold Member FABO Gold Member

            Messages:
            9,476
            Likes Received:
            8831
            Joined:
            Jun 1, 2016
            Location:
            Oceanside ca.
            Local Time:
            7:40 AM
            750 cfm doubl pump if manual transmission, quickfuel 680cfm vac sec if automatic transmission.
             
            • Like Like x 1
            • Bewy

              Bewy Well-Known Member

              Messages:
              1,312
              Likes Received:
              823
              Joined:
              Jan 1, 2021
              Location:
              Australia
              Local Time:
              2:40 AM
              The factory engineers were not dumb. Some 360s used 85o cfm carbs [ TQs ].
              The Holley would make an excellent door stop...
              Use an Edel carb. If mileage & general use is planned, the 650 AVS2 would be best.
              For greater higher rpm performance, the 750 AFB or 800 AVS would be great.
               
              • Like Like x 1
              • Agree Agree x 1
              • j par

                j par Well-hung Member

                Messages:
                28,345
                Likes Received:
                16242
                Joined:
                Jul 2, 2014
                Location:
                Portland Oregon
                Local Time:
                7:40 AM
                ONLY ONE CARBURETOR!!!... LOL...
                I've got two 625 Street demons on the duster... But I wouldn't recommend that..
                I will be getting a 750 Street demon for my up coming small block truck build...
                I have a costumer with a 750 street demon on a 400 GTO and it had the float bowls way out of adjustment out of the box... A simple adjustment and no problems.. actually it was good to take it apart as it gave him a greater understanding of how it works and how adjustments effect it.. also confidence to make adjustments...
                Whatever carb you choose keep a log of factory settings and how it acted and every adjustment and how it acted and come back to this thread x-months from now and thank me you did...:thumbsup:...
                 
              • Ricks70Duster340

                Ricks70Duster340 Child of the King FABO Gold Member

                Messages:
                640
                Likes Received:
                427
                Joined:
                Feb 8, 2021
                Location:
                Sisterdale, TX
                Local Time:
                9:40 AM
                Changing one thing at a time and keeping a log is a great idea. It's too easy to lose the rabbit when making lots of changes.
                 
                • Agree Agree x 1
                • rumblefish360

                  rumblefish360 I have escaped the evil Empire State! FABO Gold Member

                  Messages:
                  41,751
                  Likes Received:
                  13999
                  Joined:
                  Jun 21, 2005
                  Location:
                  Florida
                  Local Time:
                  10:40 AM
                  At 360 cubes, if your mainly cruising the streets and not visiting the top end much, the smaller 650avs or a Holley Street Brawler would do fine. It will respond very well on the street. The larger 750 size would provide a little bit more power over the curve you’ll notice. It’s not huge, but you’ll notice. On the big end, it’s worth about 10hp.
                  Throttle response will be good. Not as snappy as the smaller carb which is more sensitive to throttle position changes.

                  Ether will be good. If you go to a 750, I’d use the Holley Street Brawler.
                   
                • MOPAROFFICIAL

                  MOPAROFFICIAL FABO Gold Member FABO Gold Member

                  Messages:
                  9,476
                  Likes Received:
                  8831
                  Joined:
                  Jun 1, 2016
                  Location:
                  Oceanside ca.
                  Local Time:
                  7:40 AM
                  Fwiw a long time ago I swapped on a 650 dbl where a 750dbl was ..and then back to the 750.
                  The diff felt yes, a little snappier ...but after 3500-4000rpm the 750 let it pull wayyy harder.
                  In a stick car, the snap is crap compared to the midrange tq rolling in at 2000-3500 on the street..its a big diff.
                   
                • rumblefish360

                  rumblefish360 I have escaped the evil Empire State! FABO Gold Member

                  Messages:
                  41,751
                  Likes Received:
                  13999
                  Joined:
                  Jun 21, 2005
                  Location:
                  Florida
                  Local Time:
                  10:40 AM
                  Now there’s something.

                  Is this a automatic car?
                   
                1. This site uses cookies to help personalize content, tailor your experience and to keep you logged in if you register.
                  By continuing to use this site, you are consenting to our use of cookies.