well I can tell you on my end I really like the 6.2 and I am now running a p400 6.5 only because I wanted a NEW engine I pull heavy loads through the woods haul cars horses boats rv s ect. I dont even have a turbo nv4500 transmission and an na 6.2 is all you need in my opinion if your hauling through the mountains you may want to give her some boost but i get by with none no issues been on the road with my truck more than I have been home have had since I was a teenager and I will be 40 in a couple months