Scott,
Did you find the problem? Will all that has been replaced and tested, have you noticed any leaks? Do you have to top off anti-freeze every couple of days? If cleaning the radiator does not work, make sure the proper mixture of anti-freeze is used. A new rad cap would not hurt. Let us know what fixed the problem.
Sounds like you checked alot l would pull radiator and send to radiator shop to check for correct flow it only takes about 20 % of core to clog to cause truck to run hot over a long period.