UPDATE May 1st 2017 AM:
I drove the truck yesterday and the noise coming from the front of the rock cover is louder. I need to figure out what that noise is.
It sounds like a loose rocker or valve lash? It seems to be just one or maybe 2 valves, louder near number one cylinder. I hope its not a valve, valve seat, or spring. I will try one more time on an adjustment on the valve lash, and open the lash up a couple thousandths.
I'm going to carefully inspect the rocker rack, lash studs on valve stem location, and remove the camshaft. I haven't decided yet, but I am leaning towards a new camshaft from CompCams - the 252S. At this point, I'm concerned about the overlap in the 261C, but it's just my gut feeling, past reports on this cam in a 22RE, not based on any real hard facts.
Regarding the fuel pressure regulator... it's looks impossible to R&R without removing the chamber from the intake manifold. But, I will replace it.