Looking to replace window balances
Hello!
It indeed sounds like you need new window balances. Based on what I see in these photos, my recommendation would be the Series 380 or Series 385. The difference between them is the depth of the bottom fitting so you'll need to measure as shown below. You will also need to refer to the stamp imprinted on the balance's metal channel to determine the proper spring strength option. The one in your last photo is too faded for me to make out, unfortunately. I recommend checking the balance on the other side of the window to see if it has an intact stamp you can use as a reference.
It is the series 380 based on my measurements. 2920 is the option on both balances.
I'm glad I could help. Good luck with your repair and let me know if you need anything else!
We do! The part shown here is called a top sash guide. Our 18-201 was my first though but look over the specifications and see how they match up with yours.