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Technical 3x2 or 2 4bbls

Discussion in 'The Hokey Ass Message Board' started by Ron Brown, Oct 31, 2021.

  1. Ron Brown
    Joined: Jul 6, 2015
    Posts: 1,638

    Ron Brown

    Considering running a 3x2 holley carb or a 2x 4bll set up on a slightly warmed 350 sbc....
    want alot for the looks but still want it to be usable.

    pros and cons on either setup?

    going in a 1800 lb highboy roadster with TH350

    chevy57dude likes this.
  2. To me the 2x4 setup represents horsepower, the 3x2 represents hot rod, something more than the 4 barrel can offer but not up to the point of dual quads.
    It really depends on the build, 3x2 goes good with wide whites, the 2x4 goes well with magnesium 5 spokes.
    I bought a 3x2 to maybe some day replace my 2x4 in my t-bucket, but so far I just can't bring myself to do it.
  3. bchctybob
    Joined: Sep 18, 2011
    Posts: 3,336


    ^^^^ What he said. I have had 3x2s on several cars and I like the look and they ran great but you have to open up the secondary carbs frequently to get fresh gas in them and sometimes that isn't easy to do considering how much a ticket can be in California. Carbking usually recommends dual 4bbls with straight linkage and that does away with that problem. I will be running two 4bbls on the Nailhead in my '33 pickup. I haven't had inline dual quads on anything since the early '70s but they were perfectly fine back then (394 Olds w/2 AFBs) and I have a lot more patience for tuning than I had back then. Your roadster would look good either way.
    jaracer, loudbang and Deuces like this.
  4. Boneyard51
    Joined: Dec 10, 2017
    Posts: 5,347


    I’m a 3X2s man……just for the looks! Back in the day, three dueces were common, 2x4s not so much in my area. So, it ‘s three ducks for me!

    deathrowdave, LowKat, GordonC and 2 others like this.

  5. 41rodderz
    Joined: Sep 27, 2010
    Posts: 5,718

    from Oregon

    Yes sir , 3x2 for the win if you can set them up.
    Deuces likes this.
  6. I have had both but prefer the 3x2's as the traditional hot rod setup. Bob is right about keeping fresh fuel in those secondary carbs though. My latest set up will run 3 97's non progressive. That will keep fresh fuel in all 3.
    Boneyard51 likes this.
  7. Roothawg
    Joined: Mar 14, 2001
    Posts: 22,038


    I have both. They each have their place. Personal preference.
  8. BamaMav
    Joined: Jun 19, 2011
    Posts: 5,178

    from Berry, AL

    With 3x2, you can just run the center carb and block the other two off. Hard to run just one on a 2x4 setup.

    Either can be made to look good.
    Deuces and Boneyard51 like this.
  9. Roothawg
    Joined: Mar 14, 2001
    Posts: 22,038


    Sacrilege!!!! Heresy I say!
  10. Elcohaulic
    Joined: Dec 27, 2017
    Posts: 2,584


    I like the Tri-Power for looks. They do haul ass though.

    One of my all time favorites is the older Weiand intake with the stars and the Carter Thermo Quad carburetor..

    Weiand 7501.jpg
    Deuces and Boneyard51 like this.
  11. Blues4U
    Joined: Oct 1, 2015
    Posts: 6,074

    from So Cal

    To each their own, but IMO 3 x 2 has been over done. I've gone to 2 x 4 just recently.
  12. carbking
    Joined: Dec 20, 2008
    Posts: 3,193


    Assuming V-8 engine:

    Performance - single 4
    Looks - 3x2
    Looks AND performance 2x4

    EDIT: There really is no "right" answer. The above summarizes performance potential. Looks is entirely up to each individual. Price will be single four, dual four, tripower, least to most.

    Second edit: here is a link to an article you may (or may not find interesting):

    If you read to the end, there are links to other articles with supporting information.

    Your build, your call.

    Last edited: Nov 1, 2021
  13. I see no point In having a multiple carb set up with not all of them functioning, just use them all! I have dual fours (AFB) on a big block in my convertible with straight linkage as per Jon’s suggestion and wouldn’t go back. Looks and runs awesome.
    Deuces, swade41, bchctybob and 2 others like this.
  14. jimmy six
    Joined: Mar 21, 2006
    Posts: 10,242

    jimmy six

    I love dual quads. By 56 almost all manufacturers had them and very few had 3-2’s which came later. I personally like progressive linkage but understand those who don’t. I idle on both and have never have a fuel problem with the front one in 6 years. To me sizing is very important especially with street use and a non-high performance engine. (think 245 hp 283 here)
    My opinion is they both say Hot Rod. It’s also personal that I like stock or stock appearing air cleaners on them.
    Deuces, carbking and bchctybob like this.
  15. de-fenders
    Joined: Jul 10, 2006
    Posts: 651


  16. nochop
    Joined: Nov 13, 2005
    Posts: 2,377

    from norcal

    I kind of like the idea of tooling around on a two barrel, then stomp and open up all six.
  17. 6sally6
    Joined: Feb 16, 2014
    Posts: 1,784


    2.32 mining nose gold!.jpg're not gonna cam it.....and have at least 9.5:1 CR either /or will run like a dawg but 'may' impress the "air-head millennials " who stare and 'axe' stupid questions at car shows!
    2-fours with a snotty cam and plenty of thump at idle .........they do tend to get me aroused at the cruise-ins!!o_O
    Like a snotty nose............YOU PICK!
    Your choice
    rpm56, jimmy six and Roothawg like this.
  18. olscrounger
    Joined: Feb 23, 2008
    Posts: 4,399


  19. Mike_B
    Joined: May 31, 2007
    Posts: 23


    I agree that the car's style is a factor. I put a 2x4 setup on a 350 in a friend's 37 Chevy. Carbs are Edelbrock 500 cfm models. Progressive linkage starts opening the secondary at around 2/3 throttle, I'd guess. I'd have to check my notes, but I think both idle circuits are adjusted as usual, and I did some jet & rod changes based on suggestions from Edelbrock and others. The setup has zero issues, and is as well behaved as a single well-tuned 4bbl.

    Attached Files:

    Deuces and olscrounger like this.
  20. Blues4U
    Joined: Oct 1, 2015
    Posts: 6,074

    from So Cal

    LOL, I've never had a problem with fuel sitting in the secondary carb too long either! I guess we have lead feet Jim! :D
  21. anthony myrick
    Joined: Sep 4, 2009
    Posts: 8,910

    anthony myrick

    I vote 3 4s or 4 2s
    Deuces and Almostdone like this.
  22. brigrat
    Joined: Nov 9, 2007
    Posts: 5,451

    from Wa.St.

    Take your pick, one is more than the other! IMG_1246.JPG
    bchctybob, dana barlow and Deuces like this.
  23. Dooley
    Joined: May 29, 2002
    Posts: 2,750

    from Buffalo NY

    You run 2 fours.... never knew that
    BTW I'm still thinking of that one you offered awhile ago
    Boneyard51 and Deuces like this.
  24. 3 X 2s look cool, and properly tuned work very well.

    I've never had a problem keeping fresh fuel in the outside carbs, but I'm not about to let the throttle linkage go without proper exercise for long. :cool:

    2 X 4 would be ok too though. :)
    Boneyard51, Deuces and Blues4U like this.
  25. birdman1
    Joined: Dec 6, 2012
    Posts: 1,305


    Nothing says hotrod like 6x2s on a 430 Lincoln
  26. belair
    Joined: Jul 10, 2006
    Posts: 8,801


    3x2 for "the look," 2x4 for badassery. I like the spaces between the carbs on a 3x2, and the three air cleaners. 2x4 can just look like a lump sitting on the intake.
    Boneyard51 likes this.
  27. 55blacktie
    Joined: Aug 21, 2020
    Posts: 503


    To quote Blind Faith, "Do what you like."
    1929rats, wvenfield and Deuces like this.
  28. 55blacktie
    Joined: Aug 21, 2020
    Posts: 503


    Boneyard51 likes this.
  29. 55blacktie
    Joined: Aug 21, 2020
    Posts: 503


  30. Jessie J.
    Joined: Oct 28, 2004
    Posts: 395

    Jessie J.

    3x2s was the go to hot flathead setup from the 40s into the 50s, thus early on took the crown of being the 'traditional' setup.
    4 barrel carburetors did not become available until the early 50s, (1952)
    but when they did, half a dozen companies rushed into producing and selling aluminum 2x4 manifolds within months.
    Think about it. With 2 four-barrel carbs you have equivalent of 4 2 barrels, without all the leakage, linkage, and tuning problems that plagued the traditional 4x2 carb setups.
    Factory production 3x2s carburation after 1953 was no longer the actual 'Hot' setup, but the traditional eye candy bling that old and moneyed luxury cars buyers demanded.
    Cadillac going from 2x4s of '55-'57 to the 3x2s of '58-'59 was actually a step backward in both technology and in performance. They made up for it with increased displacement, but a 390 still gives its best when fitted with 2x4s. GTOs too.
    Boneyard51 and Deuces like this.

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