17Sierra6.2

Hi all, I recently picked up a 17 Sierra 6.2 and am experiencing the shudder issue as well. The truck has 61,000 on it and actually had the trans flush done in Oct 2019 at around 37,000. I am looking at having it flushed again and am wondering what the P/N is for the blue label Mobil 1 (Dexron-VI?) as P/N 9417577 is what they used before. I can't seem to track down this down.. I do also have the Range afm disabler on it but it doesn't seem to make much of a difference.