My opinion is the absolute best plugs are Iridium, but in reality they are quite pricey and also not too many people are driving a ton of miles on their classic mopar. So the only advantage would be the smaller electrode is somewhat less likely to misfire.

I doubt you'd notice a difference.


'70 Duster 470hp 340/T56 Magnum/8 3/4 3.23 Sure-Grip