I would do a Wildman or DP Tuner. I don't know about Wildman but with my DP-tuner if I want to change shift points or other stuff I just send it back and Jody does it. With the new F6 chip you can do it right over the net without sending it in, I have the F5 chip, had been on my truck for over 120K and been flawless.
Cheap Thrills Off Road
2003 F-250 4X4 7.3 PSD Crew Cab