Chevrolet Repair: 1993 Chevrolet Cheyenne, 4.3L, chevrolet cheyenne, infrared thermometers

Question
I purchased the above vehicle used.  It has 113100 miles and has a few small problems.  but , the cooling issue is bugging me the most.  I first would like to know what the normal temperature for this engine is.  It hovers at about 150 degrees or so, then drops.  I have replaced the thermostat-195*, Temp sensor, radiator (it had cracked tanks and needed replacing), and Radiator cap.  Still no change in temp. It seems to be reading lower, lately, after all repairs.  I flushed the system and replaced it with green 50/50 pre-diluted.  The only thing left I can think of, is the fan clutch is shot, but don't know how to tell if it's bad.  I don't see it leaking , but it does have a slight resistance when free-wheeling, with the engine off.  I'm totally stumped.  Unless I've done all this for nothing, and that is where it should read. Thanks in advance

Answer
Sounds like your temp gauge or sending unit is out of calibration.  It should operate at 210 degrees.  If fan clutch was bad and vehicle was running to cold the fan would roar all the time.  Find one of those infrared thermometers and test the temp of the upper hose after the t-stat opens