What spark plug to use?

Discussion in 'Chevy C/K Truck Forum' started by partsman, Feb 26, 2009.

  1. partsman

    partsman New Member

    Bought a used 1996 GMC Sierra extended cab, 4X4 long box with 7.4/454 motor, auto tranny, 3.73 gears, with 219.000Km/137,000M on it.
    I am wondering what brand and type of plug to use in it.
    Here I hope are pictures of one of them I took out tonight to look at.

  2. nightmare

    nightmare New Member

    i would go with the bouch platinum+4 plugs 6.99 at checker o'rilelly auto parts or if you can afford them deffinitly get the pulsar plugs about 45$ for 2 of them you'll get a little better mpg as well
  3. yotchie

    yotchie Rockstar 100 Posts

    isnt it true that using those fancy plugs will only make a difference if you are running boost? unless i guess as in this case they are in bad shape
  4. Pete95Sierra

    Pete95Sierra Epic Member 5+ Years ROTM Winner 1000 Posts

    i have had good luck with bosch platinum 4
  5. mjalstad

    mjalstad Rockstar 100 Posts

    OEM AC Delcos. I've heard people talking about getting better MPG and power and whatnot with a fancy plug. You are never going to notice any difference whatsoever! With certain applications such as boosted engines some people do like to use a copper plug for heat transfer reasons which I think still does not really matter. I would just go with the OEM plug because you are probably the least likely to havea problem with them. I have also heard many stories about certain GM vehciles being very finicky about needing delco plugs, probably just a load of BS but a couple of really good mechanics I used to work with say they've seen it and will never put anything in a GM but an AC Delco OEM plug.
    Last edited: Mar 1, 2009
  6. Chris Miller

    Chris Miller Rockstar 100 Posts

    Best way to figure out what Bosch plug is for you:
    Take eight of them and put them in a bucket of water. Whichever ones float, use them.
    Definitely stick with AC-Delco. They cost as much as a Platinum 4, but they'll last twice as long.
  7. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts


    That's funny but oh so true. A/C Delco plugs are designed to work in GM Engines. I just changed the Iridium plugs in my truck. They had 68K on them and they looked as new. The gap was even the same as the new plugs. Had I known this I would have left them in but I already purchased the new plugs.

    The rule of thumb is A/Cs in GMs, Autolites in Fords and Champions in Mopars. Send the rest of them overseas! <GBG>
  8. 77chevy

    77chevy Member

    That's some damnd good info! Thanks. I'll stick with delko

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