I have an 04 allison and I would like to swap the operating system out with that of an 01. I've heard they dont learn and that I would lose the OD cut out option but thats fine with me....currently every time i change the power level it's like the trans starts all over from scratch learning how to shift. As much as i would like to just hammer on it all the time, :D I do still have to drive it every day. Does anyone know how I can make this swap without having to buy the whole efi setup???

Find someone with EFI to reflash it for you and toss them $100 to pay for the license. ;)

Yon can do and OD off mod and reflash the TCM. Gm makes a kit with a dash mounted switch.

thanks for the advice....I'll be checking into it

Yon can do and OD off mod and reflash the TCM. Gm makes a kit with a dash mounted switch.

http://www.dieselplace.com/forum/showthread.php?t=231092&highlight=ODLO
http://www.dieselplace.com/forum/showthread.php?t=708
http://www.dieselplace.com/forum/showthread.php?t=152270&highlight=ODLO
http://www.dieselplace.com/forum/showthread.php?t=48880&highlight=ODLO
http://www.kennedydiesel.com/docs/Allison%20OD%20lockout%20final.htm