Can't find misfire

I've taken the head off three or four times in my appartment parking lot. I also built my entire slant six turbo setup there. The head usually takes about an hour, I take the top bolt out of the alternator bracket, loosen the bottom one, take the belt off and slack the alternator, and then pull the manifolds. Make sure you replace that little bypass section of hose when you put the new head on, it's a good time to do it. Also stick a wire down the cooling passages while you have it off.

.010 and .020 are slant six respective settings on valves, and you should set them basic static, then fire the engine up, and reset while it's running. It's a lot of fun, and super quick.

Did you try backing the valve off a little? Say .040 and seeing if the misfire straightened out?
I've dealt with the burned valve in the past, which had me pulling the head the first time, but then it also had a broken in half pushrod so I only had 4 cylinders for a minute...