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2002 5.3 plug gap?

Discussion in 'Maintenance & Upkeep' started by ratrodder, Apr 4, 2011.

  1. ratrodder

    ratrodder New Member

    I have heard i am supposed to set them at .060, and another tells me .040?
  2. 99'HEARTBEAT

    99'HEARTBEAT Epic Member Staff Member 5+ Years ROTM Winner 1000 Posts Platinum Contributor

    Your 2002" Came with A/C Delco Platinum Plugs which were Gaped at....0.60.....The A/C Delco Plugs that G.M./Chevy Is now installing are the A/C Delco iridium Tip Spark Plugs which are Gaped at....0.40.....the A/C Delco Iridium Plugs are the ones you want to go with,

    Link,

    http://www.summitracing.com/parts/ACF-41-110/

    Also the A/C Delco Plugs are already Gaped right out of the Box....Check the Gap to make sure there Gaped at ...0.40, But Do Not Attempt to Re-Gap them, as the Tips can be Easily Damaged....

    Edit:.....Now would be a Good Time to check your Plug Wires and replace if needed.

    Last edited: Dec 9, 2013
  3. 98Hotrod98

    98Hotrod98 Rockstar 100 Posts

    Great info HeartBeat,
    Just FYI to ratrodder, normally the spark gap and alot of other maintenance related things are listed in a chart in your owner manual.
  4. mudpuppy

    mudpuppy Rockstar 100 Posts

    the reason why some say .40 gap is because then they will burn better. shorter gap causes a stronger shark hence burn the fuel more efficiently. heres the down side, they will burn out faster. the .60 gap is for max life span of the plug with still burning enough fuel for proper operation. imo if i had a hotter coil i would get to about .50, if using a stock coil then around .35-.40. here again this makes alot of difference as what to gap to depending on any and all engine mods that you have done to include exhaust work. if everything is bone stock performance wise( this does not include k&n and a chip and then your have a hot rod like so many think) then i would stick to around .55-.60. if your exhaust is opened up(meaning no cats or punched cats) and/or head work done then start looking at a lower gap.

    imo, i would only use autolite plugs. my t-bird is pushing about 15.1psi boost at a flow rate of around 800cfm on a 3.8 v6 with 60lbs injectors tune to 42lbs at a 40% cycle rate and 26degree timing curve and never skips a beat.
  5. 2COR517

    2COR517 Epic Member 5+ Years 1000 Posts

    The reason for the .040 gap is more reliable firing, and longer lifespan on the rest of the ignition system.

    AC Delco (or NGK) plugs only for me.
  6. silveradotrailblazer

    silveradotrailblazer Epic Member 5+ Years ROTM Winner 5000 Posts

    Welcome to the club, ratrodder.
  7. BigBlueLB756

    BigBlueLB756 Rockstar 100 Posts

  8. stephan

    stephan Rockstar 4 Years 5000 Posts

    Thanks Blue, that's a keeper :great:

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