Pressure tested a bunch of rad caps,toss out 3 out of 4 for
fail of prsessure test.Kind of need to change these more often but Im as bad as any one looks good is good.

This has probably been done also but I had similiar problem and after all the time and parts it was just the radiatoir cap.
Old one looked fine but I changed it and no more over heating problem.

I'm sure these have probably been looked at, but just in case.
1- Make sure the fan is correct for the machine. If the fan is of the wrong rotation it can not move air properly.
2- Makes sure the fan shroud is installed, positioned properly and it is correct for the machine.
3- Check for worn drive belts and pulleys. Worn belts and pulleys allow the belts to bottom out and slip under increased load.
4- Use a 50/50 mixture of water and anitfreeze to get the best heat transfer.
5- Verify that your gauge is reading correctly.
Hope this helps and Good Luck.
Tom

this sounds good , their is not bleeding screw on the water pump ,

Also test with a digital thermometer diffrent points to see where coolant isnt flowing IE head,radiator,water pump ect

Have u tried a water flow test threw the rad ,,,,,,
ie ,, when u pore coolant in how quick does it flow
out,,, Did u pressure check the head.. is there
an coolant in the oil [ small bubbles ]