Welcome, also from upstate NY (between Albany and Saratoga) Though the CAI and exhaust may get you better numbers, I find I'm getting worse cause I love the sound over the mileage! Gears and air bag are your best upgrades to make the truck tow better. I have the v8 and superchips. does a great job in towing my Boat and Brothers boat.

 

as far as the jet chips for the 3.7l they are a waist of money. i have a k&n cia, flow master exhaust single in dual out, and trans cooler and my 3.7l does just fine with a loaded 16' trailer. as far as the leveling kit i just got one made out of solid billet from ebay for $76. tires i run 265/75/16 (monkey i would like to know why you didn't like that size?) but with the leveling kit i think you can go a little bigger with the right back spacing. i have a set of maxxis buckshot tires and they are an awsome looking mud tire that is reasonably priced for mud tires i think i paid $135 a tire and they last for ever the only problem i have with them is balanced i have had them balanced 3 times and they still vibrate a little i think its due to the mud tread more than anything but it doesn't bother me as it is only felt in the truck and not the steering wheel. but before you do anything i would check the sway bar end links and replace them if you haven't all ready the stock ones are junk and you can get them at rockauto (two of them) for the price of one at a dealership just order the ones for the 06 dak because rockauto doesn't realize they fit the 05's. hope we helped you out some.

 

oh i forgot to mention as far as towing/pulling i pulled my partners patrol car out of 6" of mud with the same set up while my truck was in the same mud had no problem but i did cover him, inside of the partol car (learned a lesson on that) and the outside of the car. oh and it a 2wd.