Finally got around to tearing in to the Yukon more. Passenger head is cracked (tested at machine shop) and pulled the lifters to find out the lifters and cam lobes are pitted and scorn with bluing which means she has heated up prior to my ownership. I also noted when I parked the Yukon before it broke down it would not get over 20psi of oil pressure.
Upon further tear down, there is a crack in the block on the driverside from what appears someone over tightening the shit out of the heads as they were replaced before me.
The truck is an utter mess and don't have the time or funds to put another long block in it. A friend of mine had recently totaled their Yukon 2500 and was offered a decent price, I may very well sell it to him so he can pull his LY6 and place it into my Yukon and he has a nice rig for his family.
I have a '06 Ram Megacab 2500 4x4 on top of the Yukon and my commuter so it makes since to just throw in the towel and walk away from the Yukon.