I agree. I was expecting a slight orange dusting, not a thick coating. I hate having ST knock, but I'll have to combat it other ways besides MMT.
I ordered a can of Redline SL1 to clean any residue in the combustion chamber. I'm sure the piston tops are dusted or coated.
I have a 13 RT and only used one bottle of the NOS racing formula and had a light orange coat like the picture, just not as heavy and mine are not iridium. Wonder if its the MMT.I doubt that one can of TORCO and one bottle of NOS in 10K miles caused that. In fact, they look very similar to mine at 14K miles. I wonder if the orange/brown is the norm for Iridium plugs as I've seen several motors with plugs like that with no octane boosters used. My older 5.7 with copper plugs looks more traditional colored but my newer 5.7 and 6.4 look similar to yours.
Are you running a custom or 93 tune? Just curious as you mentioned ST KNK. Are you running a 180 stat and lowered fan settings? Just wondering if that could be in play as well.
Redline cleaner is good stuff. I tried a few different things after I changed my plugs and noticed the color of the plugs and the Redline made the most noticeable difference. I run 1 tank before every oil change now.
Do all 14's come with iridium plugs now?