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Hei Plugs

Discussion in 'Jeepster Commando and Commando Tech' started by jackdog, Apr 15, 2020.

  1. jackdog

    jackdog Member

    I'm sure this has been answered before but I can't seem to find it in the archives so here goes. What plugs do you use when switching to a HEI dist. in a 225? Gap?
     
    jackdog, Apr 15, 2020
    #1
  2. DrDanteIII

    DrDanteIII Master Procrastinator

    When I did the HEI on my CJ, I just kept the standard plugs and opened the gap up to 0.040 in (from 0.035). Its works great
     
    DrDanteIII, Apr 15, 2020
    #2
  3. Focker

    Focker That's a terrible idea...What time? Staff Member

    Look at my signature line.
     
    Focker, Apr 15, 2020
    #3
  4. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Heat range should not depend on the spark voltage. Same plug, with increased gap. Without a dyno, you can't do any better IMO.
     
    timgr, Apr 15, 2020
    #4
  5. duffer

    duffer Rodent Power

    I think the factory spec for most GM HEI systems is 0.045".
     
    duffer, Apr 16, 2020
    #5
  6. jackdog

    jackdog Member

    Trying to remember the 2 wires that go to the HEI are 12v + and tach?
     
    jackdog, Apr 17, 2020
    #6
  7. oddfirejeeper

    oddfirejeeper Active Member

    yes 12 volt and tach jackdog. Should be moulded in the plastic stating which one is which. at least mine does
     
    oddfirejeeper, Apr 19, 2020
    #7
  8. jackdog

    jackdog Member

    Thanks!
     
    jackdog, Apr 19, 2020
    #8
  9. nickmil

    nickmil In mothballs.

    Like Duffer said, I'd open them up to .045" which is common on HEI systems. I've seen them as high at .060" but that's unnecessary for this application.
     
    nickmil, Apr 23, 2020
    #9