Don't take what I said as me thinking you caused this. I've got a better understanding of how dealers operate than most because of what I do. I don't doubt that your engine had some issues that you clearly pointed out. I'm just trying to give you help to get this resolved.
How about a quick timeline here. Purchase, install, when you found the first issue with the valve keeper and rear main seal to now. Is there a reason you didn't take it back to the dealer that did the work to fix GM's first two major blunders? I totally get you may have moved with your military service and again, it's not your fault if you did move.
Keep this in mind about certain dealers. As in one you didn't deal with originally. If the issue looks to be a pain in the ass and they didn't sell it to you, they won't mess with it. Not defending them, but dealers tend to take the path of least resistance if they didn't originally sell anything to you. It doesn't bother me, but it does bring an added degree of difficulty for sure. This is all the more reason to figure out the problem yourself prior to handing it off to a dealer most likely unwilling to go through the effort if they don't have it handed to them. For example, we sold a GM performance crate and the customer lived a couple of hours away. He experienced an issue with the oil pump making noise and took it out and went to a dealer close by. Even though they could have helped they told him to go back to the dealer that sold it to him. Hell, all they had to do was give him a stinking oil pump. Nope. He called me back, I ordered a pump and took it up myself for him.
Just like you did before, you have to do your homework. Get to the root cause. Prove what is going wrong. Know what the problem is so they can't pull any crap on you.
