Engine/drivetrain vibration?

What kind of balancing did the shop do? They will have a record of this.

If it was internally balanced, you have the wrong balancer on it if the ORIGINAL one was re-used. Replace with a forged crank dampner, or buy a new one for about $100 for a neutral balanced engine.

If it was externally balanced, the ORIGINAL dampner would have been spun on the crank, and the shop should have asked for the torque covnertor and flex plate to balance it. If they did not ask for these and they externally balanced it, they created a problem, but you should be able to use a nuetral convertor and run it.

Here's the caveat... converotrs, even neutral ones, have soem weight on them to balance them individually.(like a gets balanced) You trans shop chould have removed the crank counterweight, AND the convertor's own balance weights, making the convertor out of balance now regardless of what you do. My question is, what did the tranny guys do with the weights they took off? There are marks, they can simply re-weld them in place.

On the living with it. You might be able to... but the engine and convertor cannot. At least not for long. Out of balance means the engine is trying (sucessfully) to eat itself up. Stop driving it until you know what needs to happen.