How do you like your NGK TR6 plugs? I was doing some research and found that the plugs I had until last summer were 1 range colder, not two like believed (they were Iridium TR55IX). So I was checking out TR6'* and they look just like iridiums, except the center electrode.

What got me looking was my Autolite 5245 (3 range colder) plugs seem to have fouled.

John, our mods are similar. I had the TR55'* (one colder) and they only lasted 3 months. Went to the TR6'*, and I'm into 4 months, and they're looking great.

Kinda off topic, but can one range colder plugs run a little better then my stock range AC Delcos?

Got KR? If so, then yes.

Just swapped 'em. The Autolites were definately fouled. I may need to lean out the mixture a bit. But I'm gonna put in my A/F gauge tomorrow or Monday to get it right.

New plugs = satisfyling power linearity AND MUCH LESS SHUDDER!!!

I've still got a little that I need to narrow down, possibly ohm check the wires.