hi im new here and have been reading about the spark pluges for my 20004by 4 i went down to orielys parts store to get new plugs and ask the guy what it took he said ac rapid fire and i put them in and runs great .and now in reading on your post to only put platnum in .will it hurt with the rapide fire plugs?

You'll get the best performance and fuel mileage with AC Delco platinum or double platinum plugs.