I use 92 octane Chevron or Shell and recently put in some Techron hoping (but not believing) that it would clear up, The fuel filter is one thing that was on my "to do" list but somehow missed....can't believe I forgot.
I believe the plugs are copper core, I put a empty plug box in my MB file so I would know what to order next time, So I will check it out and get back with the answer.

And finally......NO, I did not reset the base fuel mixture at hot idle after completing the head job. Can you point me to the right place that would go over this procedure? I tried finding information on if there were things that needed to be done once everything was back together. Maybe you (fdm alex) if you have some time, could let me know what I am missing or point me in the right direction? I would be perfectly happy with a list of procedures/jobs that get done after a job like that and I can take it from there with figuring out the rest.