Thanks everyone!
Correct. It has the 3.73 and i do use the tow/haul mode. Just double checking cause 3k seemed high as this was the first "big" thing I've towed outside of boats and snowmobiles.
Took a trip last year to Smokey Mountains. Got really nervous when trans started heating up through the hills(~200). Have made it a practice to have it flushed and new filter before long trips. Live in Wisconsin. Heading to Kentucky this spring break.
Had heard that GM was going to put diesels back in surburbans. Might be happening for 2019?? Don't know if i can stomach $80-90k though.....