I don't know if this has been discussed but has anyone seen any differences in performance from the AC41-993 Iridium compared to the AC14 Rapid fire in a 93 4.3? As of now I have been running the standard copper core RT44lts (Marine) due to the fact that I had them on hand from my boat and my local box store was out of stock when I had a major fouling issue of the above listed plugs. Just looking for some feedback I know the 41-993's performance but the comparison is what I'm interested in. Thanx!