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NGK Laser Iridium Performance Spark Plugs (03-04 Cobra; 07-14 GT500)

Item 64019
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Market Price $129.99 You Save 15% ($20.00)
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$109.99 (set of 8)

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      Product Information

      Features, Description, Reviews, Q&A, Specs & Installation


      • High Performance Replacement
      • Improves Fuel Economy and Lower Emissions
      • Heat Range: 6
      • NGK Part# 4477
      • Fits 03-04 SVT Cobra and 07-14 Shelby GT500
      • Sold as a Set of 8


      Regular Maintenance. Replacing your old weak spark plugs is paramount to keep your engine running smoothly and efficiently, so why replace them with the same old sub-par stock plugs when high performance plugs from NGK will improve fuel efficiency and lower your emissions.

      Superior Construction. NGK Laser Iridium Performance Spark Plugs feature an iridium disk that is welded on the center electrode and a platinum disk that is welded on the ground electrode to reduce the wear rate of both surfaces ensuring greater durability and longer life. NGK uses pinpoint precision laser welds to reduce excess debris decreasing the required voltage to bridge the spark gap for a more efficient burn.

      Application. This set of eight (8) NGK Laser Iridium Performance Spark Plugs are specifically designed as a direct fit replacement for the 2003 to 2004 SVT Cobra and the 2007 to 2014 Shelby GT500 Mustang equipped with the supercharged 5.4 liter V8.

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

      MPN# 4477

      CA Residents: WARNING: Cancer and Reproductive Harm -


      Customer Reviews (10)

      Write a Review

      Ratings Summary

      4.3 out of 5 overall rating from 10 customers

      Installation Time: Less than 1 Hour

      • October 24, 2018

        5 2003 Cobra - Tracy Installation Time: Less than 1 Hour

        NGK Laser Iridium Spark Plug

        Very good product, this is the third time buying theae plugs for my 03 Cobra. This pair is for the new Pro Mod Stroker engine 5.0 i had purchased for the car

        Helpful (4)
      • July 21, 2018

        3 2010 GT500 - RooseveltG

        3 Stars for this reason...

        Ok so the reason these get 3 stars is because these plugs are NOT pre-gapped. If your mustang runs a 0.050 gap then you'll be fine. Otherwise CHECK THE GAP BEFORE INSTALLATION! Got mine installed, buttoned up and only to not start up! Back to the drawing board and doubling of my work time! Gap was way off on the plug so just take 30 seconds to check and adjust them. Trust but Verify! Otherwise, Great Plug

        Helpful (6)
      • May 19, 2018

        5 2012 GT500 - IurieB Installation Time: Less than 1 Hour

        Shelby gt500

        Great product and fast shipping.exactly as described

        Helpful (5)
      • July 17, 2017

        3 2004 Cobra - RedTerm Installation Time: Less than 1 Hour

        Great plug! Terrible Packaging!

        I know it's says to focus on the product and not customer service on here but the plugs speak for them selves. Great plug, worth the money. Packaging was terrible. Spark plugs were loose, out of their box. Only one set came in a box of four, the other four were loose out of their single box, rattling around during shipping. Not ok! Install took a little longer than normal just because every single one was closely inspected for damage.

        Helpful (7)
      • November 26, 2014

        5 2010 GT500 - BenWaller Installation Time: Less than 1 Hour

        NGK Iridium Plugs

        Great producer and great customer service. I definitely recommend this product.

        Helpful (7)
      • January 26, 2014

        4 2003 Cobra - Rydogg Installation Time: Less than 1 Hour

        Easy install, great fit

        My stock spark plugs have been in the car since 03, took less than an hour to install, no hassle at all no huge noticeable power gains...but im sure my engine and supercharger are very happy with my decision.

        Helpful (8)
      • February 18, 2013

        4 2008 GT500 - Skinny420 Installation Time: Afternoon

        Plug Upgrade

        I changed from OEM plugs just before 50k miles. The old plugs did not look pretty. One wasn't even screwed in tight and there were obvious signs of blow-back. Yo can't go wrong upgrading your stock plugs to these iridium plugs. It was a little tricky getting the old plugs out, so take your time and do it right. I also painted the coil covers Ford blue while they were off. Couple hours worth of work that's totally worth it.

        Helpful (8)
      • October 14, 2012

        4 2003 Cobra - King03Cobra Installation Time: Less than 1 Hour

        No noticable gain

        Was great plug, look amazing, though had to adjust every plug's gap, which isn't hard. I have had the plugs for over a 2k miles, and haven't noticed any increase in mpg, quicker start ups or throttle response. But this plug was the best money for the mileage, which is 100k where the other plugs rating was 50k miles worth of use.

        Helpful (7)
      • July 30, 2012

        5 2003 Cobra - Cobrafiend Installation Time: Less than 1 Hour

        Great Plugs!

        Straight forward. If you are running higher boost (pulley, aftermarket s/c...) check the plug gap. It's a bit tricky, but gently tapping the grounding strap is the only way to do it.

        Helpful (7)
      • March 27, 2012

        5 2003 Cobra - AndresGarza Installation Time: Less than 1 Hour

        Wake That Pony Up!!!!!

        Wow! These spark plug's Kick some Serious Tail! Now you would think that spark plug wouldn't give you any Horse Power, But these plugs increase performance. And do alot more then what they say they can do! My buddy has a 03 Mach 1 and he was looking for some Laser Iridium plug's, and told me that AM dosen't carry them for the 03 Mach 1. But that he went to his local O'Reilly's and got them for 12.00$ a plug. Just go to show you good things come to those who wait, And better things to those don't! I think you should go buy you some of these plug! So get off your a** and go buy some!

        Helpful (9)

      Questions & Answers (1 answers)

      1 Top Rated Question

      what should these be gapped at on a minor modded 04 cobra. Mods are catback exhaust, CAI and 93 octane tune.

      • The factory gap is all you need to have on them. The only time you would ever need to adjust the gap would be with aftermarket cams or nitrous.

      Helpful (0) Show 1 more answer
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      Installation & What's in the Box

      Installation Info

      What's in the Box

      • (8) Spark Plugs

      Tech Specs

      Will It Fit My Mustang

      • Cobra - 03, 04
      • GT500 - 07, 08, 09, 10, 11, 12, 13, 14

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