I have been like a cat chasing his tail but finally I made progress.
My 2004 F250 6.0 started idling rough, losing power when hot and would die at idle sometimes. I at that time did not have the ScanGauge II so I checked the FICM which was 37 volts when running. Off the FICM when to ED for repair. I cleaned the EGR valve which it needed and waited for the FICM. Got the FICM back and found that one battery had failed. So purchased two news batteries and a ScanGauge II. I put that stuff in but still had rough idle, losing power when hot and would die at idle sometimes. Put the ScanGauge to work but did not find any codes and HPOP pressure was good.
One of my neighbors is a mechanic so took him lunch for advice. He listened to it for a few minutes and said you’re starving the girl for fuel. We took off the secondary fuel filter cap and it only had an inch or so of fuel present. I ordered the blue spring regulator kit and put that in. When taking the old stock fuel regulator off I noticed two things. The orifice at the top of the housing was stopped up which bleeds air out of the housing and back to the fuel tank and the check valve o-ring was flat not round that regulates the fuel. I started her up and notice she was better but still not right. After the 15 minute drive and getting air out of the fuel lines she’s much better. I also installed a test fuel gauge and its holding steady at 65 PSI.
I noticed a small amount of black smoke from the exhaust so I working on that now, maybe the EGR valve. But hope this helps others and thanks all for your suggestion, could not have done it without your help!