Jeff your right but it wouldn't be clutch or speed related. The got worse when the clutch is in
is a real clue....If he left out the pilot bush the clutch would center randomly and would do the shakes at idle.
I know there are other thing that can do this but as always we must guess....
I once had a noise in the 228 and vibration like this It was a chunk missin from the FAT fan belt
it slapped and knocked like a piston
