Well since FMC discontinued the SP542 plugs, I thought the SP578 was the correct one, since the number supercedes the SP542. Come to find out that I should running M-12405-35T. Which is basically the plugs for the FORD GT with the EcoBoost motor. From what I was told that the 542s where fouling out.
I'll see how the 578s working for now, then switch over. The 578s are colder than the 534s I was running.
Oh here are the 534s I pulled out, I put new plugs in when I switched tuners. I had some gap growth of .007. Plugs where gapped at .026. I had the same growth when running Livernois tunes.
First pic is cylinders 1, 2, 3. Second is cylinders 4, 5, 6.
Yes I was told I didn't drive my car very angrily. Haha