Been putting it off for a long time, truck just turned over 125000 mostly trouble free miles. So today with the help of a friend we changed out the water pump, fan belt, upper and lower water hoses and thermostat, tensioner and both belt pulleys. Pulled the lower plug out of radiator, took the thermostat out and drained.
Filled with water from hose and let it run for 45 minutes on high idle with the heater running full blast. Drained it and refilled it with distilled water, drove it around for about twenty minutes, drained it and filled up again with distilled water. After driving it that time we pulled thermostat and water pump and replaced with all new parts. Topped it off with Rotella Long Life Antifreeze.
While I was at it, I put on a water filter. So that's my Christmas present to myself and my Ford F-350.