1987 vintage sash balancers

I have a double sash window that won't stay in place. Both balancers have broken springs. The cases are stamped with 11600-3 on one side and 11600-17 on the other. In addition, one has BE13 9427 2-87 (with the "4" very light and smaller) and the other has BE19 9427 2-87 (also light "4") but they came out of same window.
Which balancer is the replacement?