I've been looking through some threads discussing spark plugs and I have to say, the more I read, the more confused I get. So correct me if I am way off here. I am running headers, downpipe and ubend delete, intake, and pcm to be slightly tuned, nothing major. I also ported the sc a little bit. I will be running the stock sc pulley to start but hope to drop a little bit, (due to only small mods) somethime in the future. So with that being said...should I go one heat range cooler (I believe it is) with something like an Autolite 605? Thanks in advance for the input. I admit upfront I'm not much of a "gearhead" forgive the term. But when you start getting into technical combinations of mods, heat ranges, pulley sizes, knock retard on and on...my head starts to spin. I try to keep up and educate myself on here but sometimes I just get lost and need to ask for clarification. Thanks again.