How much more power does the 6.2 have over the 6.0? My BIL has a Chevy 2500 with the 6.0 pulling a 30' camper, 8400lb. He says it's way underpowered. He's in lower gears all the time.

“In a time of deceit telling the truth is a revolutionary act.”
― George Orwell

It's not over when you lose. It's over when you quit.