Thanks for the info.
I may need a new sender/gauge. I have changed the thermostat, temp sender, viscous fan, and water pump. The problem is that the gauge will go past the half way mark (never close to the red line) after about 10 mins of driving, and then settles real close to the center line. Once I kill the engine and start ip back up again the gauge reads below the center mark and never goes back up until I kill the engine again.
This has never happened until I had the radiator out for service and the heads worked on and the cam/timing chain & gear replaced (upgraded).