360 torque converter

Those "later 340s" that were externally balanced were ONE year only. 1973. So it stands to reason the odds are on your side to have an internally balanced 340. You do need to double check, though. Also, I wouldn't just "knock the weights off". I've seen people do that and knock a hole in the converter knocking the weights off. That would suck. I would get a cut off wheel and carefully cut the weights off.