360 Balance Question

If the motor and tranny where in your other car as a pair,and the car did not have a vibration then,and does now,you have a drive shaft diffy angle problem.Mopar torque convertors can only be installed one way,people have tried to install them wrong.If no weight was removed during the install,the vib is in the drive line.Look to see if the two weights are still there,one on either side of the drain plug in the convertor.You can buy a special flex plate to counter balance the convertor and remove the weights to use any convertor.You could have a bad drive shaft/pinion angle that is causing the vibration due to the install,Mrmopartech