5.9 no power but a story to go with it.

[stevesparts]

Have you disconnected the batteries. and let it sit for a bit(hr) then hook them back up. then the ecm might relearn as you said the key was messed up and you fixed it so it might just need to rethink its settings,it worked on my 95 5.9 12 val. but that was a different problem.(kid owned it before me,alot of aftermarket crap,ran like sh#t)
plus there are alot of crap someone could have done to it with the keyway messed up.
and i would try some of the dodge truck forms for a better answer as they would likely have had a problem like this on there.