I'm curious as well, is this a DD?
Setting the tires lower will help but if your back is that bad then doing this won't improve it enough to make a big difference. I'd figure out a way to make the seating arrangement more comfortable for you. Where does your back hurt?
Try placing a pillow or rolled up sweat shirt in the arch of your lower back. Or maybe lean the seat back a little. Try different things until it becomes tolerable. I just don't think you are gonna be able to really make a difference in the truck without changing something major and undoubtedly expensive.
Honestly the air ride seat is not a bad idea, certainly an aftermarket company has stepped up by now and offers something???
