I started out years ago towing our 7,000 lb trailer with my old chevy 2500 with the 350. I tow mostly in the Sierra and Rocky Mts. I hated the way I had to slow down to 45 mph going up the grades. So ...
I agree with you guys. But regearing and the tuner for me was more about driveability than pulling a grade at or above the speed limit. It made towing with the V-10 on flat ground much more pleasant and relaxing. Not to mention I picked up almost a full 1mpg better due to the motor being in the proper power band (gears) and it not shifting goofy at even at the slightest headwind or overpass (tuner).