how to set up a harmonic balancer so it works for magnum engine

PRW 2431841: SFI-Rated Racing Steel Harmonic Damper Small Block Mopar 273-360 | JEGS I ordered this harmonic balancer, which comes with interchangeable weights. However, it doesn't seem to have come with much in the way of instructions on what weights to put on for what engine. How do I figure out what weights to put on for a 360 magnum

Yep, the medium weight.
I just did the same thing and the link Bobzilla posted is when I asked.