Window balance channel

At first glance, it looks like you can use our Series 377 channel balance as a replacement. This comes assembled with a 19-018 top balance shoe and 15-005 bottom balance shoe. Take a look and see if you agree. I am a little confused about the length of your balance. You mention that it is 27", however, your stamping of "3030" and "3040" indicates to us that the metal length measurement of your balance should be 31". I strongly suggest reconfirming the length of the balance.