Gapping Iridium Tip Plugs????

[barbastard]

Just bought some AC Delco Iridium tip spark plugs (PN# 41-985) for my 6.0L and want to confirm that these come pre-gapped correctly and that you are NOT supposed to alter the gap any. Is that correct? I heard something that these plugs can’t be adjusted any due to the Iridium tips. Is that correct?

Plus I picked up some Taylor Thunder volts (8.5mm) to throw on as well….hopefully looking forward to some improved performance and better gas mileage between the two.

Also…..just to let you guys know…there is a guy selling sets of these plugs on ebay brand new for $30. I bought a set and had them shipped to my door for $36 total. Much better pricing than from the chevy “stealerships”

[chrisj6]

I wouldnt regap them, they are gapped a bit differently than what your truck would call for, but that is due to the iridium tip.