What spark plugs do you recommend for a 1998 GMC K2500 with a 5.7L engine.

I have heard that some plug brands do not perform well in the 5.7

Thanks for your input
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Ac Delco is the best way to go.

 

I use Champion.
AC Delco would be a good alternative.

 

You cant go wrong with original equipment. For over 50 years I have watched people screw different plugs in hoping for 20 more HP or 10 more miles per gallon and I beleive I can safely say it aint gonna happen. In the cases I have had where plugs created a problem it was because the heat range was wrong for the conditions. I have had cases where a company would reccomend a cooler plug to protect their engines, but when operated on light duty the would foul. (International Harvester) Learn to "read" your plugs they will tell you the story,cyl to cyl.