Hello guys, when I got the car (before I found this site) I did a tune up that included plugs. I bought the hottest iradium triple headed blah blah blah the guy said would work. Well, now that I have half an idea of what I'm doing I have starting scanning and noticing knock. Basically, since I'll be installing headers this weekend I want to replace my plugs with either just stock or even one range cooler. Reason being I live in New Mexico and I have hot thin air.
The question, has anyone tried the autolite xp605 vs the normal 605. Autolite says they are the same heat range but with more durability. Any ideas?
TIA,
Slim
