I am familiar with rod balancing under normal circumstances, as Elwood points out you match to the lightest rod. I've had rods balanced, shot peened, and reconditioned with new rod bolts for mopar small & big blocks in the past. They have the balance pads needed to make them a matched set.
I admitted my idea was probably unworkable, because of the potential for damage to a given rod. It was just a passing thought.
Since you can apparently balance them by smoothing out flash and so on that makes more sense.
Elwood, are you able to get replacement rod bolts for these motors ? Eventually I see myself building one of them,and am curious about that.
Too bad the 218/230 rods don't have balance pads like their bigger brothers.