H405CP versus stock magnum 5.9 pistons

I am curious because I have 2 360 magnum blocks (one already 30 over) and my son has a set of the 405 pistons in 30 over that have very low miles on them, he built a 76 360 then rebuilt it again as a 408, one day I'd like to combine his pistons and one of my blocks, if that would be possible. I know that the 360 mag while still external balance, was a lower balance factor than the old LA version. If we were to use everything else Magnum, but with the 405 pistons would we use a balancer and flywheel weight for a magnum or for an LA? And for the record this will be a "one day down the road" build, as we have too much other stuff going on besides, right now to worry about it right now. Just convenient timing for someone to bring up this topic is all. Putting it out there for the benefit of the group "only" at this moment.