Does a video count? I took a short video of me hauling a load in our C3500HD truck at work this week. The truck weighs 10k sitting their empty since it has a hydraulic dump bed. I had it loaded down with mulch, im going to assume 6-7k pounds, so gross weight should have been 16-17k pounds. Not a light load. The truck has 4.63 gears and the 19.5" wheels. Its totally stock aside from a heath injection pump and PMD. Its a pretty decent grade and its long enough to slow you down pretty good if you are loaded heavy enough, but I thought the 6.5 handled it very well. These engines are much more capable than most people give them credit for. They aren't torque monsters but they have a very linear power band.
I did hit the hill in 3rd gear with the converter locked because I knew it would downgear anyway, plus ive always felt like these engines like to rev. They are smooth in the higher RPM's. Went back to O/D once I crested the hill.