before i go and tear everything apart tomorrow if anyone wants to reassure me i'm heading in the right direction, or not that'd be great...
Obviously the truck is new to me, but it made a 3hour (one way) trip, running ~190 (aftermarket gauge). I've been cruising around town a little bit, no problems. I did have a bad gasket on the radiator cap, changed it to a new 13lb cap, and it started overheating at idle right away. It kind of just fixed itself.
Drove it around town here and there, up long steep grades, no sweat. 180-190 is all the way.
Today, put a new injector install kit in. Idled it for a while to get the air out, it slowwwly creeps up to 190, then after that it cruises pretty quick. I shut it down once it passed 210. Let it cool off, tried it again, same deal.
Being so intermittent, i'm thinking thermostat. What say you?