Thank you. I took your advice a couple days ago and called my dealer and also got parts ordered and I’m just waiting for a call from them for set up. Thanks for your help.UPDATE...
UPDATE...as posted above chips were ordered last Wed. 7/12-dealer called TODAY 7/19 said my chips are here and scheduled for install next Wed.-said it takes about 22 hrs. So if you're waiting for that letter from GM call your service dept. and get em ordered.