Hey my cousin has a 99 cummins, it is 4x4 with an auto. She's wanting to swap to a 5 or 6 speed which ever we can find and or is cheaper. Just looking for some input on the subject. I have completed 2 auto to manual swaps so far without any problems in my first gen cummins and my 95 powerstroke, both were 4x4. I am just curious if the the ecm will function properly and stuff like that. AS for the linkages and crossmember i can figure it out, any advice would be awesome thanks, Chad.