I removed the intake tube that runs from the output of the turbo and attaches to the top of the engine in order to gain better access to my PMD harness plug. If someone could tell me the correct name of that tube I'd appreciate it. Anyway, at the end of the tube where it attaches to the intake manifold there are two circular openings through which air from the turbo goes into the intake. I was surprised to find a considerable build up of black gooy crud at the end of this tube, just where it attaches to the intake. One side was worst then the other. The stuff was soft and came out easily, I removed it and cleaned it up with varsol and reinstalled it. I was wondering there this stuff might have came from and I'm thinking that it is formed from the crankcase fumes that the EGR valve feeds back into the intake. Just got the truck last December so I don't know how long it's been since someone had this off. Is this a normal thing to have happen? I probably removed 2 tablespoons of the stuff in total. BTW the truck runs fine, no codes and uses very little oil. Any thoughts would be appreciated.

That's the upper intake plenum where the MAP, and IAT sensors and EGR valve are.

Those two tiny holes are complimentents of the GM engineers to control EGR flow back into the lower plenum. You can disable the EGR and cut the castweb out and have a better truck IMO.