Ford 6.8L V10 Vacuum Line Diagram
 

I think I found the source of my engine troubles.


Here you can see it sticking right out in plain view in the open, I feel really stupid for not seeing this. The way the smaller hose wraps in a coil should have given it away too.
http://www.drewhawkins.com/images/2000_f250/1.jpg


Here you can see where it leaves the intake manifold and where it is literally just sitting in the hose adapter.
http://www.drewhawkins.com/images/2000_f250/2.jpg


After pulling the heater hose off, and the PCV valve, inspecting the smaller hose that connected them shows that its not one hose but two joined by a small threaded pipe, like you would find inside a table lamp!!!!
http://www.drewhawkins.com/images/2000_f250/3.jpg



Here is the partially repaired view, I used a 5/8" Elbow at AutoZone marked "Ford PCV", the 1/4" to 5/8" and a 10" section of new fuel hose.
http://www.drewhawkins.com/images/2000_f250/5.jpg


Here is the emissions control label on the hood.
http://www.drewhawkins.com/images/2000_f250/6.jpg

http://www.drewhawkins.com/images/2000_f250/7.jpg

The diagram clearly shows the line coming from the intake and then splitting into two, one going to "Main Vac", and the other to a "FPRC", which is related to the Fuel Pressure Regulator.

The PCV valve is labeled to be connected to "Main Vac", but not shown where on the diagram.

I have the vacuum line from front of intake to the PCV valve with not other connections. Which according to the diagram is wrong.

Should I have replaced the PCV valved? Do they go bad?

Also a big thanks to everyone here for their ideas and suggestions.

Moved to the V10 forum.

I have all the diagrams for the 2007 model, let me know if you need something.

He has a 2000. The 2007 isn't going to be the same.

The PCV valve IS shown on the diagram (on the left).