This truck was used till the engine locked up from overheating. I bought it and installed a used engine out of a van. The engines was both P codes and there was a few items that had to be changed to make it work in the truck. After install and 15 qts of oil I started back tracking and can see that the oil filter housing is not filling up with oil and the gauge on the dash is not moving. I changed both oil pressure sending units and also changed the barrel valve and spring from behind the harmonic ballencer. Still can't get any oil to the top of the engine. Any help before I remove the engine again?

Its your high pressure oil pump that has gone bad. Basically in the 6.0 model and other Power Strokes if your HP Oil Pump goes then you will not get any oil up top and your vehicle will not start. It's a safety device of sorts, because if it fails while driving it SHOULD shut the vehicle down. The 6.0 doesn't have feeder valves like the 7.3 does so that that eliminates having to pull the bottom end apart. The only other likely cause is that you did not fill the High Pressure Oil Pump with oil, try adding some oil to the pump and see if you can get it to start pumping oil, they sometimes also just need a good cleaning if they have been sitting for some time.