Harry,
I agree use racing fuel on a new setup, once you know were you are you can go down on octane.
Strange it's between 3&4, normally between 2&3 4&5 show the most heat since there are two exhaust valves together.
Did it push in one direction like from 3 to 4 or 4 to 3 are the ends curled in towards a cylinder or just burnt away?
The A/F meter was it a wide or narrow band, was the O2 one wire?
Since I'm not sure a cometic will seal the square water passages at the plugs, you may want to try a copper gasket, I use a rubber coated copper from Flatout gaskets in Illinois.
Harry
Last edited by Turbo-6; 08/12/12 11:34 PM.
