I found out what was causing the full manifold vacuum I was seing in the crank case. Dealership performed a diagnostic test on the engine that measures the resistance of each cylinder in the firing order when the starter turns over the engine. The test identified that the #1 cylinder had 35% relative compression. The Ford tech said the low reading indicated a bad cylinder. He said air is passing around (or through) the #1 piston which is creating the vacuum in the crank case.
I found a low mileage replacement (from a roll-over) and I am planning to pull the old enegine this weekend. I will pull the head and post back if the diagnosis from the dealership was correct.
Has anyone else had this problem? My truck only had 104,000 miles.....so to say I am disappointed in Ford and their engines is an understatement.