Some clarification on this new balancer please?

I threw the outer ring on my Magnum harmonic balancer/damper and this one was recommended by Summit racing.
Problem is, the sales guy couldn't tell me which weight to use for the Magnum, nor if there were specific instructions included with the balancer on which weight to use.

PRW High Performance Sportsman Harmonic Dampers 2331841

Anyone know for sure?

Thanks
Hey I remember that post. Oh yea because I made it. Lol but a agree it is very frustrating trying to install parts when it comes with 3 diffrent weights and no instructions on which one goes with which engine. Lol also I be upfront and say I am not very impressed with this balancer. What I am talking about PRW must only put just enough powder coat on it to cover it and that's it. The frist one I got almost all the powder coat was rubbed off the back and some of the outer ring wear the timing Mark's were. Also one of the counter weights was lose in the box and just floating around. I will say summit took it back with no problems and sent out another one, before I could send the bad one back.
Ok got number 2 in the mail. Its got some of the powers coat missing in the back. But just one little spot that you cant see. At least this one the outer edge looks good and doesn't have the powder coat worn off. I needed to get my dakota running and didn't feel like wating another week to get number 3 Balancer.