JT I have an auto, with a set of Bosch 300 injectors and the stock cam plate moved about 3/4 of the way forward it made my truck a lot more of a towing machine than when it was stock. When stock it couldn't hold speed up a grade and forget about trying to pass someone on a 2 lane road.
I also have done 215 injectors with a #10 plate in the middle, a little less power but lower EGT. Anyway with either combo I wasn't lacking for power towing my travel trailer (20 foot 1968 Terry) 60-65 up pretty steep grades and 70+ on lighter grades.
The 300 and 215 injectors are fairly inexpensive if you can find them used, there are some to be found on eBay too. Same thing for the #10 plate, or if you look around here on the board you can grind your own plate for some free HP.
I forgot to add, I've done all my towing with these power upgrades without doing a darned thing to the transmission, except I changed the oil once. Have towed quite a few miles. Virgin transmission has 186,000 miles on it, so far it's doing OK. One biggie is when you're getting on it or taking off with a load is to upshift it manually. . . get the RPM up. I upshift at around 22-2600 RPM, not the stupid 1600 RPM Dodge has programmed. And don't use OD until you can keep the RPM above about 1700, that'll help it (and keep from getting EGT too high).