I have a new tow vehicle its a 2006 Yukon Denali XL. This weekend will be my first time hauling with it. My trailer is about six and a half thousand pounds loaded. The truck is a 6 liter and all ...
The 6.0 liter is quite a bit more motor than the 5.3. You might be able to run 4th in tow/haul mode. Give it a try and see how it goes. I run mine in 4th with and without tow/haul, but I have 4.10 gears which probably helps.