Don't know about the converter, as I am a 4 spd guy myself, but a 360 balancer will not work on a 340 cast crank. A 340 cast balancer says for 340 only cast into the weight, which should be on the motor side of the balancer.

1974 Dodge Dart Sport 340 4 Spd Endless Project 1999 Ram 1500 CC 5.2 5 speed