Ive got an 03, 305hp, auto, 4wd. Im competely stock for now, but that will soon change. I cant afford for my truck to go down though (work truck). So, before I up the power I need to beef up the trans. Whats the #1, right out of the gate mod I need to do to keep my truck on the road after engine mods? Where do I get it? Installation? How much? Thanks!