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NGK Iridium IX Spark Plugs - Heat Range 7 (03-04 Cobra; 07-14 GT500)

Item 64070
Market Price $99.99 You Save 10% ($10.00)
Our Price

$89.99 (set of 8)

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    Features & Details

    • Perfect for Increased Boost
    • Iridium Tip for a Constant Stable Spark
    • Improves Fuel Economy and Lower Emissions
    • Heat Range: 7
    • NGK Part# TR7IX; NGK Stock# 3690
    • 14mm Thread Pattern
    • Spark Plug Reach 0.708"
    • Fits 2003-2004 SVT Cobra and 2007-2014 Shelby GT500
    • Sold as a Set of 8
    High Performance. Keeping your Mustangs high performance engine running smoothly and efficiently is important, so routinely replace your old weak plugs with a new set of NGK Iridium IX Performance Spark Plugs for constant reliable spark power. The Iridium IX plugs from NGK will provide improved throttle response, fuel efficiency, lower emissions, and will reduce fouling.

    Superior Materials. NGK Iridium IX Performance Spark Plugs feature a copper core electrode for its superior conductivity and an iridium tip (which is 6X harder than platinum) for it's extremely high melting point, perfect for keeping your Mustangs high-performance engine running at it's peak. And as an added bonus the Iridium IX plug features Trivalent Metal Plating for it's superior anti-corrosion and anti-seizing properties.

    Application. This set of eight (8) One Heat Range Cooler NGK Iridium IX Performance Spark Plugs are specifically designed for the 2003-2004 SVT Cobra and 2007-2014 Shelby GT500 Mustangs that are running more boost.

    Fitment: 2003 2004 2007 2008 2009 2010 2011 2012 2013 2014 Details



    CA Residents: WARNING: Cancer and Reproductive Harm -

    What's in the Box
    • (8) Spark Plugs
      Hardware included:
    • None Required
    Installation Info
    Tech Specs
    Will it fit my Mustang?

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        Questions & Answers (1)

        1 Top Rated Question

        would these be good for a boosted mach 1 running about 10 psi?

        • We recommend checking with your tuner as they will be able to advise which spark plugs will be best suited for your vehicle.

        Helpful (0)
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          Customer Reviews (6) Write a Review

          Overall Rating 4.7

          out of 5 stars

          Installation Time:Less than 1 Hour

          • Performance Gain 4.333333 4.3
          • Fit 5 5

          • 5/5

            Installation Time: Less than 1 Hour

            June 02, 2019

            Perfect for increasing boost

            Definitely need to get this if you plan on increasing boost perfect product extremely happy.


            Year: 2014 Submodel: GT500

            Helpful (0)

          • 5/5

            Installation Time: Less than 1 Hour

            April 30, 2018

            nice n sparky

            had put them on recommended by my tuner (my application gapped at .028) for the tune i was going to run and they work awsome in my gt500


            Year: 2013 Submodel: GT500

            Helpful (8)

          • 5/5

            Installation Time: Less than 1 Hour

            April 12, 2018

            Reliable Spark Plugs

            The plugs are well made and arrived quick. I am running 12 lbs of boost in my GT500 and needed a colder range plug sp I figured I would try these. I gapped them to .032 and installed them in less than an hour. I've noticed better throttle response and better fuel economy. I would recommend these to anyone looking for a better than stock plug.


            Year: 2007 Submodel: GT500

            Helpful (7)

          • 4/5

            Installation Time: Less than 1 Hour

            February 28, 2016

            GT spark

            I recently purchased these spark plugs for two reasons. 1st- because I installed some upgrades and my GT 500 started missing after about a month and a few miles. 2nd - The current ones were just a little worn and gapped wrong. Yes, I closed the gap on the old ones and improved the problem. When I installed the Iridium plugs there was noticeable difference in performance. I would recommend these to anyone that may have installed bolt-ons that increased the amount of boost from factory levels.


            Year: 2009 Submodel: GT500

            Helpful (9)

          • 5/5

            Installation Time: Less than 1 Hour

            May 29, 2015

            spark plug

            this is a great product I recommend this to every Cobra owner. you could tell the difference in this product


            Year: 2004 Submodel: Cobra Waco, TX

            Helpful (7)

          • 4/5

            Installation Time: Less than 1 Hour

            June 10, 2013

            Good product, easy install

            Decided to change my plugs out at 30K miles. Old stock plugs had lots of carbon build up and looked pretty worn out. Getting the old plugs out and new ones in was a breeze, but I took my time so finished it in about 2 hours. Didn't notice any performance gain, but acceleration is smooth. AM prices on these plugs is very competitive.


            Year: 2011 Submodel: GT500 Phoenix, AZ

            Helpful (9)

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