I haven't read all of this thread, but I have my own opinion about this problem.
First of all, I agree with 1Fastdog regarding the ring swap, if that is the route you decide to take. It's not a big deal. I think GM provides a loner during the fix. Correct me if I wrong. If I had a oil burner, I would first do this. Drain my Mobil 1, and fill with a 5W30 petroleum base oil, and drive for another 2500 miles or so. This should stop the burning. I have never heard of trying to break an engine in with synthetic oil! It can be done, but it takes about 12,000 or more miles.
I had one customer who dynoed at 315 with 10,000 miles and 326 with 44,000 with absolutely no changes to his engine except the mileage. What does that tell you.
I would then install Torco's semi-synthetic T4R Racing Oil which has a ring sealing additive called poly iso butylene. The alcohol burning dragsters that ran this synthetic blend reported much better compression, and less blow by than any other oil they had used. The benefit of the synthetic part of the blend was better e.t.s
My former background: I was the Technical Support Manager and Southwestern Sales Manager for Torco Racing Oils for 4 years. Torco has been a big name in Racing Syntetics and Parafinic base oils since 1950.
We had customers like Warren Johnson, Connie Kaletta, Alan Johnson (Brother and engine builder for Blaine Johnson before his death, Elmer Trett, Star Racing, and hundreds of other race teams and a multitude of professional engine builders and I can tell you this. None of these guys ever tried to break in an engine with synthetic oil.
The reason is simple. Synthetic oil is too good. Mobil 1 has a base oil of poly alpha olephin, which has lubricity far beyond the standard petroleum oil. If there is a downside to synthetic base oil, it is that it cannot hold as many addtitives as the parafinic base oils.
Many of the racers used chrome faced top rings, which will not "wear in" if they cannot wear.
Once the rings have fully seated, a change to a synthetic or quality semi-synthetic would be my choice. Mobil 1 is ok, but there are many superior synthetics on the market. Torco, in my opinion is one of them.
Jim Hall
P.S. I do not sell Torco Oil, I just use it.
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