[DisillusionedPrepper]

Hi Irish,
As I just stated above, switching to a full synthetic WILL show case leaks if anything is marginal. It may take 1-2-3 hundred miles or so but they will show.

There are several manufactures of Synth. oil that have addressed this on their web sites so this is not just a matter of "my opinion".
On the plus side, if you do not show leaks or if you do, and repair them, you will know that your engine is as clean as it can be as well as being protected.

I am a firm believer in Synth. oils for the advanced wear protection they provide along with the improved mileage, and extended oil change intervals. They do pay for themselves in the long run.

Edit:
Forgot to really answer your question.
Amsoil is one of the top brands in oil. While I have never used it, I do know several people who do, and like any top brand oil... no lubrication related problems.
I think this holds true for any major brand of 4t oil