I hate to revive this thread, but personally I have been running the copper 104's and they worked great with me. My friend just bought this car from me and he doesnt want to bother with copper plugs. Which iridium plug is the same heat range as the AL104's? He will only consider these iridium plugs so no other recomendations please. I know I saw an actual chart comparing these heat ranges somewhere between some major brands but I did a search and can't seem to find it anywhere. Thanks in advance. I have the basic 3.4 setup on the car with mods listed in sig....
