Looks like you need to replace rods B&C with rods that weigh closer to the rest. Ideally rods that are babbitt type that have been cut for insert bearings. Is this correct? I don't know of any around here right now but will be on the lookout at swap meets ect. Maybe someone else here or at stovebolt has a set of rods with the same problem, the 2 sets could be combinded to get both parties clooser to equal weight. I would love to see a picture if possible of one of the rods. Wish I could do more to help. Jay