Hunter11,
Looks like the 3.73's do help out since I see 190 temps just running in town sometimes 170 to 185 is typical after about 1hr running around in stop and go traffic.

 

Hamilton,
The truck seems to handle it just fine, with the exception of the tranny temp problem. An adjustable power chip is a definite plus when towing something this big. I've towed 19K with mine, not counting the trailer weight, long before I had my TST P3 and the truck still did it but lacked the power to keep the TC locked. I don't think 12 to 13K is too much for these trucks, but it would be much better with a standard.