For a head that has 2K or 4K miles on it, I would not touch it. More miles? Yeah, freshen it up. Unless there seems to be something visably wrong, it is not worth the time. That is just IMHO.

As far as oil passges, don't blow through them yet. Pull the two galley plugs at the end of the common galley. What's in there? I am wondering if in the cleaning process, all the crud did not get shoved in there. Pull the oil filter adapter too.

Michael