For the OP

Your pics are small because you used the wrong forum codes. You accidentally selected the thumbnail codes.

Here is your first pic:


Regarding your coolant loss, you may have a leaking EGR cooler. That coincides with your EGR valve being gunked up. When they leak, the coolant goes out through the exaust, unlike leaking head gaskets which will usually blow out the degas bottle. That coolant mixes with the normal carbon buildup in an exhaust system, and turns into carbon paste gunk.

To try to nail this down, park your truck with the nose down and the tail up. Pull the EGR valve again and look down the hole for signs of wetness or even pooled coolant. That will be a dead giveaway that you are blowing coolant into the exhaust stream.