Spring coil balance replacement

I have 2 of the same windows needing coil balance replacement. They are Amerimax , installed 11/2005. I went through the warranty process with Cascade for the first window and this took a long time. My second window problem happened after the initial warranty request. They sent me 2 balances that have no name or part number shown. I would like to verify that they are the correct balance for my windows and find out the correct part number(s) so that I can order a set of balances for my second window.

Window width 34 inches. Height 16 3/8 inches. Weight 13.4 pounds. Photos added.

Thank you.

Tim 

I would like to add that these windows do not have factory notches in the jam and I do not have jam spreaders. I will be cutting the jam to replace the balances and would appreciate any tips that you can provide for this process. Thanks again.