factory specs say plugs should be gapped at .040, but these plugs are at .045. just wondering from those of you who use them, do you reduce the gap to .040, or just leave it at the set .045? I just got them, and am having a hell of time reducing the gap to .040, so just wanted to know what you all did with them

thanks

 

I have never run any plug on any vehicle with the gap they come out of the box with. Plugs should always be regapped to meet the specs of your vehicle before you use them the first time. With 3923's, the stock gap of .040 should be fine, but I like to gap mine a little tighter then spec, like about .038, so they are less prone to misfire. Some go as tight as .035 on 3923's. If you have an aftermarket coil that is hotter then stock (like MSD), then you could get away with a .045 gap.

 

I agree. When I bought my ngk's they were gapped at .044. I put them in like that and the truck ran like crap. I re gapped them to .040 and she ran great!

 

well, im still having a rough time with reducing the gap on the plugs. anyone have any tips on how to do this? all i have is a simple gap tool (the round kind). i dont want to mess anything up.

 

I usually just lightly tap them on workbench a bit until they measure correctly. It's really pretty hard to mess up. If you go too far, bend the side electrode out a tad and re-measure.

 

I never use those round universal gap tools. Needle nose plyers, or a gap tool like the one in the pic below is what I use. The little tabs at the bottom are designed to grab the ground electrode (the neck) and turn it down or up while keeping it level with the center electrode (no twisting). It works really good. Also, a tool like the one below or a feeler gauge is more accurate for doing the gap because it allows you to measure across the entire surface of the electrodes evenly. The round universal gap tools use a surface that is gradually getting thicker, so you will show tight on one side of the electrode gap, and loose on the other. And if you try to use it to increase the gap, you can twist the ground electrode so that it is higher on one side then it is on the other. You can also break the center electrode by trying to force something between the electrodes to increase the gap. You should only touch the ground electrode when decreaseing and increasing the gap.

[IMG]local://upfiles/9095/B05085A6559E468995AE6262176F3BF3.jpg[/IMG]

 

thanks guys...all set now, im good to go, truck is running nice and smooth now.