I've cleaned up these two used balancers, and for got which is which. One has lots of stampings, the other not so much. They both, have the same general casting numbers. The one on the right has a hand stamping of, 19S, the other no stampings on front, but several smaller casting number. One motor is a 1971,TR, the other a SF, 1970. If any body wanted to keep the balancers separate. It just dawned on me the with two cranks having the same casting numbers, the balancers being different, must be due to the pistons being different, which they are. If someone wants to buy a crank, it wouldn't make any difference, with out the correct pistons?
If the balancers have a date code, you might be able to tell that way, I don't know. Looks like the balancer on the right has bigger balance holes. Which pistons are lighter, 70 or 71? Have you tried to weigh the balancers accurately? Just spitballing here since no one is answering.
ultimately if someone buys both the crank and the balancer, and they're that far into the motor it needs to be balanced anyway (your comment on pistons is just one of the reasons.). If someone just buys the balancer as a replacement part, they can replace the pins in the appropriate location to match the balancer that came off the car. I wouldnt worry too much about matching them to the crank. Nice looking pieces both!
I was hoping someone could say something about the 19S stamped on the balancer on the right. They are used balancers, and I guess they would be okay for a budget cruiser, not performance. I had not noticed the pins, didn't know they could be moved. I will get a closer pic of the stamping on the left balancer, in the right pic. I has a date, I think. I just listed the blocks, heads, and cranks, on the board this morning. Looking for a delivery to GS Nats, in May.
