replacing channel balance

Hi,

Your website is great - pictures and videos are really helpful!

Half of the windows in my 30 year old house have at least one busted window track. I'm attempting to repair one window and if successful will do the others.

Starting with replacing channel balance in 35w x 19h kitchen window.

Definitely 19". Based on website pictures of top and shoe, pretty sure I need the 19" Series 371 Channel Balance Product Code: S371-19. My photos attached for confirmation.

Don't know sash weight range or which of the 4 stamp options to choose. Current track is stamped with ' 18 D' and 'B.S.I.'. Please advise which stamp option I need.

Thank you!
Tom

Thank you, the window weighs 16 pounds so I ordered the 1840 option.

I also ordered (1) 18-124: LH Top Sash Guide, Rollyson and (1) 18-123: RH Top Sash Guide, Rollyson, just in case needed. Do these serve a function other than cosmetic? (Update: now sold in pairs, see 18-124P)

Some channel balances on other windows have busted up through the plastic sash guide and the channel balance is visible when the window is closed. Are any other parts typically needed when replacing the channel balance? For example is anything needed to hold it in position next to the sash?

Thank you.

Thanks, Paul.
To totally redo a window, is anything else needed other than channel guides and top sash guides?
Thanks.