BTW, when you plug that fitting on the valve cover, I would check to make sure that the vent slots on the valve cover are clear. I am actually surprised, BTW, that when installing the PCV kit ( which includes adding that fresh air inlet fitting ) the instructions do not include plugging those vents. At least I did not see that referenced in the instruction sheet posted by phak1.
It seems strange to me that they would have the installer go through the trouble of installing that fitting (which provides filtered air to the crankcase) and still leave the slots open - which would be a source of unfiltered air.
The instructions on the sheet I posted were from the Factory Assembly Manual. They were instructions for the truck assemblers to install the PCV system at the factory and not retrofit the engine for PCV. The valve cover would not have the vents or they were plugged at the factory.
