Overheating?

[SargeSlaughter]

Long story short, I had an ect sensor code, changed it and went for a drive. Water pump puked all over on the freeway so I pulled it off and swapped it and the thermostat. Temps never went over 224 according to my monitor getting off the freeway. Now the truck runs 224 driving around town in traffic once moving drops to 210ish. 208ish on the highway. Prior to, never went over 197. Changed the ect again, same problem. Removed the tune I had, same problem. Changed the fan clutch, same problem. Cracked the thermostat housing and heater hoses to see if it needed to be burped, same problem. Not losing any coolant, no white smoke from the tail pipe, no milky oil. Truck runs fine otherwise. Any ideas what might be going on here?

 

2004 5.3 LM7

 

Edit just used and block tester and fluid, repeated 5 times and no color change so I'm guessing heads are fine

[silveradosid]

defective thermostat put it in a pot of water with a thermometer and see what temp it open and if it is opening all the way