So I was driving my 04 LB7 this weekend and I noticed that when I come to a stop and idle the oil pressure goes down to about 15psi (the last white line on the gauge before the red lines). Also it feels like the truck is idling a little bit rougher than usually, although I'm not sure if it is or if it is just me being paranoid. Any ideas?

totally normal. Mine idles at 19 when warm.

I check the oil to make sure no fuel or coolant in it.

Brian