80Z Sparkplug cross threaded.

Discussion in 'Tips 'n' Tricks Topic' started by GBar80Z, Jul 26, 2017.

  1. GBar80Z

    GBar80Z New Member

    Jun 23, 2017
    I think I cross threaded one of my sparkplugs when I replaced them 20+ years ago when I was a kid and I just discovered it now that I'm starting to restore it. Is my head toast or can I fix the threads some how? Can a machine shop re-tap the threads?
  2. 70-camaro

    70-camaro Veteran Member

    Mar 25, 2010
    marietta ohio
    It can be fixed with a heli-coil. It is easy to do with the head off. The machine shop should be able to do this for you.
    GBar80Z likes this.
  3. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

    Nov 4, 2004
    Ringgold, GA
    If the threads aren't in too bad of shape, you may be able to repair with a spark plug thread chaser tool, may even be able to rent it from AutoZone or Advance, etc. Do a Google search, you'll get a lot of info. Otherwise, it's best to go the helicoil route.
    GBar80Z likes this.
  4. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

    Feb 26, 2004
    Bloomington, MN
    Chase it.
    I did that with a plug on my old 305 that I got from a salvage yard in the 80s.
    My son is still using that engine and the cross-threaded plug hole has never caused a problem.

    You just have to be VERY careful you get the plug started in the correct set of threads the next time you change them.
    GBar80Z likes this.
  5. budro6968

    budro6968 Veteran Member

    Apr 2, 2016
    Jax Florida
    If it is a stock iron head you could find a cheap used one and use it if the threads are too bad.
    GBar80Z likes this.

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