360 harmonic balancer: the new 1 can't be right?

Myron (Locomotion) is correct on the DA-3602 part number. At least for the LA 360 externally balanced engines. This is the exact balancer I have for my 360 which was externally balanced (1979 Block).
I don't think the aforementioned people who posted about your question were "Really" trying to flame you. Their all here to help. These guys are good guys believe it or not.
Yeah... I have been rattled by them a few times, but they don't mean no harm.
Welcome to the forum by the way.