I have a '99, 2500 CTD 3. 56 with an AT.
My buddy "had" a Ch&vy dually, but after driving my dodge he went shopping for a Dodge. He bought a 3500 HO with the 6speed, 4. 10. He tows a 10K lb 5th wheel. I tow a 6K travel trailer. (dry wieghts)
If you looking to max out the GCVW of the truck and towing abilities, the 4. 10LS, HO w/ 6speed is real sweet, I thought the transmission was very smooth. Running empty, you can skip a gears, and with all that torque, the clutch is nearly useless...
I've driven my buddies truck, and it's great. The 6 speed is real smooth. The power is great. With the 6 speed, the 4. 10 vs the 3. 56 isnt a real issue. The Ls they offer with the 4. 10 is a nice reason to get the 4. 10.
He put the dodge aftermarket J-Brake in... I helped turn some wrenches and snapped pixs. . not a hard jop, and again it works well.
http://www.tdr4x4.com/rigs/bo3500/jb/
We went camping up state NY and with our difference in trailer weights and setups, we kept up with each other, and on the longest of step grades, I admit I lost steam a bit before he did, even though he tows a heavier trailer... that 6 speed and HO lets you find a sweet spot easier than the AT.
We camped at the top of one mountain. One the way up, his 6 speed had an easier time of it with the twist and turns up the steep grade than my auto did. And on the way home, down the hill, he had more control with the Jbrake and MT than I did with the AT... I rode the brakes a heck of lot more than he did. I could find a nice speed of about 25mph in second that provided some braking. . but the AT isnt built for that, so I've read. Plus 25mph was too fast for some U turns coming down the mountain.
If you towing on flat open space and dont need to push the GCVW, you'll probably be fine with the AT, but here with the mountains... I wish I had the HO and 6speed.
Best of luck with making a choice. But after driving and towing with both, I know what I would do today... .
Didn't have such a choice when I got mine.
It's not that I don't like or enjoy my truck... It's all relative, not many folks and pass others while towing, 75mph (+), on the upstate NY long grades.
Or pass a pain in the a$$ jetta at 95mph on the flats while towing. .
But his '01 HO 6speed is real nice.
Bob