I'm going to have to get back to you. Until last night, my assumption was that all the single hung windows in my house were the same size. Apparently my front facing and rear facing are slightly different.
I have 1 window in the house that is a different height than the rest. I don't have the original channels in this window to confirm length. I'm confident it would have had the same top and bottom fittings.
How do I measure for the correct channel length without the original window balance?
[Personal note: Bedroom]
Visible glass height = 27"
Window Balance length = 28"
Sash weight = 17.8 lbs.
Thank you for all the help. I've submitted the order. ORDER NUMBER: 2144283.
The entire process is/was much simpler than I really expected.