350 Chevy operating temp

[arcticmutt]

check the temp going into the heater core and then the one coming out see if they feel about the same if not you may have a plugged heater core or air in the lines if you think that it may be air remove the radiator cap and high idle the truck to bring the temp up then when the thermostat opens the level should drop when it does fill it up and put the cap back on and see if that helps any