Update,
Truck is at Industrial Injection. They performed their own diag on it to make sure what my mechanic found was correct. Ran into some issues with them not hearing the sound, had to drive back down and show them. Not so sure how they couldn't hear it, its constant and loud, but I digress.
They were adamant that I did not have a head gasket leak. I explained exactly how my mechanic diag'd it before with removing the dp. I took the mechanic for a ride so he could hear the sound under power, and they said they'd take another look.
They got back to me an hour later and said, admittedly with foot in mouth, that it was indeed a head gasket issue that they had never encountered before. The leak is at the back of the head hiding under the up pipe. It's very small, and somehow missed the oil and water passages since i'm not burning or leaking any fluids.
Truck should be back to me by Monday. Fingers crossed there is no issues with the head.