Dillon I know it's a dome but it's number of mm above the top.of the jug isnt as great as the depth to the plug of that head even with it sticking out into the head as jbot noted.
And is it a known fact that it's bad for the plug to extend onto the head that way! I understand cosmetically and ethetically it's not nice.
I took a ride with the old head with the decomp and yeah it got pretty heat soaked. 450 plus. Forget that , the only way that's ok is if I live in antartica. But because the bike ran semi ok otherwise, this evening im going to try and get the jailing on the bike using the remove the frame to.motor bolt and lifting the frame up. It's possible though that the too deep plug on the treats head is overheatingthe plugs and heat fouling each and every one that I get the engine to fire up with. So I could instead of replacing the head bolts to 126mm I could try the jbot washers and perhaps that's the whole problem. And Pats observation will be accommodated with washers. I assume I need to find 14mm washers???