I use Autolite 103's, which are the same heat range as the AC42's or Autolite 23's used in stock heads. The plugs for the GN1's just have longer threads.
OK, no luck with stockers either. Think I'm gonna try O-ringing the heads and using Fel-Pro wire lock gaskets. PITA, where are my Iron heads? I've now seen this on another set of GN1s, a little leakage passed the fire ring on the head side just above the starter. (#4) These were installed at Cottons so I know they were done right. Above average power on both cars and not much knock but some. I can't see 5 degrees of knock killing the gasket so quick, but as power goes up I know it's more critical to get it right. Now the choice, Cometic or reciever groove and wire lock gasket.
Leaking on BOTH sides, block and head cyl #4. Just a little, everyone else OK. Maybe a little more torque would have done it. I'm gonne try Cometic gaskets before I O-ring.
Yup, the only thing with em is you gotta retorque. After I great care putting her together, the last thing I want to do is take the headers and valve covers off to retorque. Not sure but I think Cometics don't require a retorque.
why would you have to take the headerds off? i would rather retouque it than change it, besides i am gonna use trw pistons and they have a low compression ratio(7.95 to 1) i figure that the shims will bring me up to like 8 or 8.25 (max 8.5) and never have any headgasket problems. and they are only $15 each to boot. seems the easiest sure route to me.