LS1 Spark Plugs - what you guys run?

Discussion in 'High Tech Retrofits' started by sbca96, Jul 2, 2014.

  1. sbca96

    sbca96 Veteran Member

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    So, I got the valve seals done, grommets, seals, valve covers and bolts torqued.

    Time for plugs. The ones I took out are AC Delco #12, I see that AC Delco #6 is
    recommended with a gap of .40 rather than the #12's gap of .60. Seems that it
    was changed by GM in 2003, gap went from .60 to .40. The #12's lasted 125k so
    I am tempted to just get them again, but the gap bothers me - so go #6?

    I know there is talk of NGK, but since this is SUCH a pain to get too, I don't want
    to skimp or open myself up to fouled plugs.

    Granted the above part numbers are for Iridium, and I do not have the income to
    support that price hike. Seems the AC Delco #6 is a mid-level long lasting plug.

    Tom
     
  2. Protour-Camaro

    Protour-Camaro Veteran Member

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    I use the plugs my crate engine came with. I think they are 2004 Corvette AC Delco plugs...500hp, runs mids 11s. Plugs don't need to be high dollar pieces. OEM works.
     
  3. sbca96

    sbca96 Veteran Member

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    So that is the AC Delco Iridium plugs then? I'm leaning toward a Rapid Fire with
    the miles I have on the engine, I doubt it will see another 100k ... but is that a
    #12 or a #6? Autozone claims the #12 is wrong for the engine, though that is
    where I bought them from. Oreillys shows the #12 as an option. So gap wise the
    "correct" plug is the #6 from the GM bulletin.

    AC Delco copper is 2.30 a plug or 1.80 with rebate.

    AC Delco rapid fire platinum is 4.99 a plug or 3.99 with rebate.

    AC Delco double platinum is 6.50 a plug or 5.00 with rebate.

    AC Delco Iridium is 6.99 a plug or 4.99 with rebate.

    Tom
     
  4. sbca96

    sbca96 Veteran Member

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    Autozone had 7, Napa had 4 .. Orielly had 9 .. and on sale for 3.99. I should get
    another dollar off that with the rebate : which goes on all year BTW.

    So. Installing #6's today.

    Tom
     
  5. Bumpad_Z28

    Bumpad_Z28 Veteran Member

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    NGK's
     
  6. 70PTRS

    70PTRS Veteran Member

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    ^^^^^^ What he said
     
  7. sbca96

    sbca96 Veteran Member

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  8. Randy S

    Randy S Veteran Member

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    I run NGK TR55's.
     
  9. Aceshigh

    Aceshigh Veteran Member Lifetime Gold Member

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    GM engineers obviously decided to improve on the design, but your experience proves the existing plug also works to 125K.

    Either choice would be good I'm sure, and I'm also an NGK guy but factory plugs are obviously proven to work well.
     
  10. sbca96

    sbca96 Veteran Member

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    Well, I'm sure that NGK plugs work fine, perhaps even better than AC Delco, but
    my concern is how long they last. A candle that burns twice as bright lasts half
    as long. Most you guys look at the MOST you can get in HP, I just want decent
    power (fun factor) and longevity.

    Tom
     

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