It seems like every shop online or in-person has their own variation of what OE plugs are. I bought me a set of 41-902 AC Delco Double Platnium plugs to put in this weekend. I went to a couple parts stores, and they told me to get iridium plugs as OE. Yet, RockAuto recommended platnium as a replace or even copper. Guys - do I have the right plugs for a 98 K1500 5.7L 350?