2004 GMC Sierra 1500 5.3L Engine Spark Plugs

[turboaz1987]

Just checking about which iridium spark plugs to use in my truck.  I installed AC Delco 41-162 plugs based on Summit Racing & Parts Geek websites but other sites say they aren’t a fit.  Engine runs fine but gas mileage stayed about average.  I changed plugs & wires around 97k miles. AC Delco 41-985 iridium plugs were in the engine from factory.  Any one know of any issues?

[Brian715]

 They had double platinums from the factory for 04 5.3l. As long as you stay with an AC Delco plug, iridium vs double platinum isn't going to make any difference in fuel mileage. 

[sefiroxx]

Tsb came out updating my spark plug to iridium and changing the gap distance.