I would not advise anyone NOT highly experienced with pulling loaded trailers to duplicate this, but I used a 16' dual axle trailer (weighed at the dump, truck and empty trailer combined weight was 6700 pounds - over the GVWR of 5350, no trailer brakes) to haul a bobcat (I don't know their total weight) about 50 miles round trip. I was at the time, still running 33's on stock 4.10 gears. Takeoffs were extremely slow, but my tired 22r-e got the job done. Braking was slow, but manageable, but required paying extreme attention to what was happening around me. I have OVERworked my truck many times, and it has yet to back down. I have since swapped to rear disk brakes, and have pulled other comparable loads, and the braking is a lot better.
Low range is very useful for getting heavy loads moving........
Either leave it in low if you're stuck in the city, or start in LOW,1st; and double clutch out of LOW to HIGH,1st