It's been a while so I thought I would update this thread. The rough idle went away and it's been gone long enough to say it was the head gasket. The idle got slightly worse right before replacing the head gasket. It got to where at idle you could feel a small vibration even when warmed up and feel something wasn't right. The coolant would very slowly disappear. The major thing I noticed was I would lose heat because the heater core is the highest point in the system so coolant it lost got replaced by air which went to the heater core. The coolant reservoir would seem to have either pressure or vacuum built up even when cold. There wasn't any visible coolant in the oil. There wasn't an obvious spot on the gasket that looked bad. I took the heads to a shop to have them checked and they weren't cracked. Not sure if they were warped. Anyway, I replaced them and all of the gaskets and seals you encounter while it's torn down that far. I didn't bother replacing timing components because I had done them about 15k miles ago. With what the shop charged me for the heads, it came out to a little over $500. That's with me doing all of the other work myself.