Hedman Header 66104 Clearance

Discussion in '1970 - 1973 Specific' started by woodpeeler, Apr 24, 2017.

  1. woodpeeler

    woodpeeler New Member

    5
    0
    Jun 27, 2010
    Minneapolis, MN
    I am in the middle of installing a ZZ6 into a 1973. I have installed Hedman 66104 headers. They went in OK with the exception of the drivers side and the lower control arm mount. I have read several posts about this same, common issue. After a little modification with a socket and a hammer, I have managed to get about a 1/4" of clearance between the LCA mount and the header. I am running OEM style (new) motor mounts.

    Does anyone have any experience on how much clearance is enough in this area? I don't want to cave the header in any more than I need to, but I don't want to have a problem after I have everything back together...
     
  2. Green hornet

    Green hornet Veteran Member

    962
    115
    Oct 11, 2015
    North Bay, CA
    I have a similar issue on the passenger side. Different Hedman headers. I didn't have to dent the headers but I can only slip a business card I between the tube and the control arm mount (just checked). If I stack two cards together they won't fit. I have had no issues.
     
  3. woodpeeler

    woodpeeler New Member

    5
    0
    Jun 27, 2010
    Minneapolis, MN
    Thanks a lot for checking. That makes me feel better!
     
  4. larrylarry

    larrylarry Veteran Member

    1,292
    37
    Dec 22, 2011
    San Antonio Tx
    What about when the engine moves side to side when reving it. Moves from left to right about an inch unless you have solid motor mounts. Just saying??
    Might not be a problum on the left unless the engine rebounds but on the right...
     
  5. woodpeeler

    woodpeeler New Member

    5
    0
    Jun 27, 2010
    Minneapolis, MN
    Good point. That is my big worry. I don't really want to go to solid motor mounts. I would be hesitant to beat another 3/4" of clearance out of the header too... Header.jpg
     
  6. larrylarry

    larrylarry Veteran Member

    1,292
    37
    Dec 22, 2011
    San Antonio Tx
    Mine is tight at that same spot on the left side. I thought about cutting the pipe going into the flange, grinding out what was left inside the flange hole then standing on the pipe to force it back in & welding it, didn't do it thou. Thought it might give me about 3/8 more gap. As it is now there's about 3/16 gap.
    Headman headers also.
     
  7. Green hornet

    Green hornet Veteran Member

    962
    115
    Oct 11, 2015
    North Bay, CA
    There is a video on YouTube about denting headers. It shows how much you can dent the headers and have no issues. They run the engine on a dyno to show how it affects the engin performance. They beat the hell out of them. Check it out. I was impressed.


     
    Last edited: Apr 25, 2017
  8. larrylarry

    larrylarry Veteran Member

    1,292
    37
    Dec 22, 2011
    San Antonio Tx
    Yeah I saw that a few months ago. But who wants there headers looking like that?
    Long time ago I had 2 different kinds of headers on a 69 Chevy truck I had.
     
  9. woodpeeler

    woodpeeler New Member

    5
    0
    Jun 27, 2010
    Minneapolis, MN
    Do you have any issues with the 3/16 gap? I think I might just go with what I have and see if it works.
     
  10. larrylarry

    larrylarry Veteran Member

    1,292
    37
    Dec 22, 2011
    San Antonio Tx
    Mine are wraped with header wrap, it does wear a hole into the wrap & wears away the paint. It thought it might cause leaking at the flange/header gasket but I haven't seen that happen.
     

Share This Page