I just towed my 2001 2500HD 8.1 weight is around 7,000lb and on a 20' full deck trailer around 3,200lb, I run the GT4094 ran lv4 on PPE hot+2 ET and if I didnt shift down to 4th when I hit some 6% grades at 2880 feet Boost started surgig at 22psi and was getting the surge sound,and egts climbed to around 1400 but in 4th gear at 65mpg pulling the hills it dropped to 1000 and was twisting 2900 to 3000 rpms,pulle best on lv 6, I think truck would work great with a set of 4.10 gears for towing with this turbo.