Getting a header to match my heads

Discussion in 'High Performance Modifications' started by Macsouthcarolina, Apr 20, 2020.

  1. Macsouthcarolina

    Macsouthcarolina Member

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    I’m finishing up my winter upgrades and am having trouble with a header-head combo that works. I bought a used set of hookers but the headers gasket keeps blowing out. Ordered a set of summit headers and my mechanic says they will do The same thing. My heads are ProMaxx aluminum 2169 and have a D shaped exhaust port shape. The headers have had a round shape. I talked to ProMaxx and they said any straight plug heads will work, my mechanic says not so.... any wisdom out there for me?


    Here are the heads https://www.summitracing.com/parts/pmx-2169/questionsanswers?page=3
     
  2. 1980RS

    1980RS Veteran Member

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    I found our if they are Hooker super comps, you have to use their gaskets. I have run into this on my Camaro SBC.
     
  3. flht99b

    flht99b Veteran Member Gold Member

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    Ran into that with the newest heads on the GM crate 425hp (not) 383 SBC. Ultra with a round hole worked if I remember correctly. We were using Hedman mid length but they also had. D port long tube also.real problem is the top of the port is taller but header bolt hole are in the stock location.
     
  4. Macsouthcarolina

    Macsouthcarolina Member

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  5. Zspoiler

    Zspoiler Veteran Member

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    I have a set of Doug Thorleys "Big Tube" headers in my 1979 Z-28 with a Supercharged 377 small block with Edelbrock Performer RPM aluminum heads. I have used a composite and or copper gaskets with no issues And no clearance issues,Maybe you could contact them .Good luck to you.
     

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  6. Z28zz383

    Z28zz383 Veteran Member

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    I have the mid length dougs headers with the d-port collector tubes. Using gmpp fast burn heads with the d ports and have had no issues. Fit and finish are great. 5 yrs+ since install, no rust and still look good.
     
  7. Macsouthcarolina

    Macsouthcarolina Member

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  8. Z28zz383

    Z28zz383 Veteran Member

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    Believe these are the ones They also have long tubes with the 13/4'' collectors for more performance gains.
    Doug's Headers D304-R 1 5/8" 4-Tube Shorty Header
     
  9. jeff swisher

    jeff swisher Veteran Member

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    I always lay the gasket I am using on the heads and notice how it fits.
    NO overhang into the port. If there is I will trim it so there isn't.

    Then I lay the gasket onto the header flange and see how it fits.
    I need the header port to be the same size as the opening or larger if it is not I port the header flange.
    Many times I need to weld a bead or 3 on the top of the header tube against the flange so I can raise the port on the header.

    I actually like the header port to be larger all the way around than the port on the head. But only a tiny bit.
    Get a little anti reversion flow that way.
    I have had to weld a sealing bead on the flanges and file them flat to make some headers seal.

    If all the above is good and you still blow header gaskets then coat both sides of the gasket with
    ULTRA COPPER gasket maker.
    That stuff will seal them up.
    Install it to the gaskets stcik them on and assemble the headers to the heads. Do not crank down on the
    header bolts really tight until you let it set up for 8 hours then snug them all the way and let it set up overnight before you go driving.
    Sometimes I have doubled up header gaskets and applied Ultra Copper on all surfaces to make them seal up.
     
  10. Macsouthcarolina

    Macsouthcarolina Member

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    I almost order Doug’s Headers D308, but their tech guy said they wouldn’t work with regular clam shell motor mounts. If what I ordered doesn’t work they will be my next choice.

    I ended up ordering Hedman Street Headers 66104 https://www.summitracing.com/parts/hed-66104. They have square ports and are 1 3/4”. Hoping the bigger size and square ports will solve the issue....Hopefully they won’t hit the passenger floorboard like the others, but I’m assuming they will since both the HookerS and Summitts did.

    considering ordering ceramic booted plugs, I’ve burned up boots on 2 different sets so far just in initial cranking of the car tuning everything
     

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