Magnum 5.9L vibration

First would like to say sorry for all the problems you are having. I have never heard or have had a converter not fill up all the way. Making it out of balance. Make sure your converter bolts are tighting all the way. They maybe to long or your converter lug threads not deep enough and the bolts are bottoming out before they are tight. Also make sure your front pump bushing is not worn out
But to me if it was worn out enough to make it vibrate that bad. That your pump seal woukd be leaking

This same thing happened to me. Good Point. Glad you reminded me ! On my first go around I found one of the bolt holes in my new TC that wasn't deep enough so I had to fix that, and IIRR the manufacturer { Turbo Action }said I would have to change the front bushing.
This new TC used larger bolts, but that was no problem since the B&M Magnum flexplate was made for them. So I bought the bolts from TA, the HEADS were SHAVED-for a close fit, but I forgot the Locktite. I need all the help I can get.
These cars are one Giant frustrating Puzzle to me. Love it !
You guys on here help me more than you will ever know and I appreciate it!