360 Balance Question

I get a vibration in the steering at 40mph and and at other speeds above that.
I think the 727 and 360 in my duster were split and now the external balance on the torque convertor is off. Is it possible the flex plate and convertor were not marked when they were removed and installed and now are in a different configuration?

I had a shop remove the 360 and 727 from my wrecked charger and put it into my duster. Well after lots time work, I have the car moving again (they just dropped the engine in for me, I did most everything else). They closed shop about 6 months ago and I cannot get ahold of them to find out what they did.

If the convertor balance weight is my problem, what can I do to fix this? Do I need to remove the tranny or engine (I currently lack the equipment to do the latter)?. Can I just un-bolt the converter and try it in a different position? Any information or details on how to fix this would be greatly appreciated.
Thank You
Aaron