I run the Denso Iridium plugs with the thin electrode and they work perfect in my engine. I just picked this plug by happenstance at work one day. I had My Indy heads on the bench at work assembling them and I was doing a tune-up on a new Tundra and just screwed a plug in my Indy head they fit perfect and I just put them in for break in. They ran perfect on the initial test drive so I left them in and I'm on my second set in 5 years
Gus