Do I need to add more info for someone to respond? No replies yet 
Have you removed the driveshafts, and inspected the u-joints, how is the carrier bearing. Do you get a shudder when the OD engages? How many miles on the truck? The vibration, is it with the truck pulling only, or does it go away when you let off the throttle?
I am having the same problem with my 99 f350 or was i should say , it started with OD, then it started doing it shifting into 3rd now it has started doing it in 2nd , with the same power loss as original poster has , i was told it was the torque converter ( shutter ) by a couple of shops and this was a normal problem for the Power strokes from 97 to 01 and i am scheduled for replacement on the 26th , i guess my question is has anyone else had this problem and was it a problem as i was told it was ?