Hi Swisco,
I am hoping to replace 6 non-tilt channel balances on large single hung windows in the community room of our local community center. They are 1/2" channels and appear to have 19-005 tops. The shoe has dimensions matching the 15-004 but the compound pully hangs from the shoe & the end of the channel as opposed to being rivet mounted. The length of the channel is 37" and the marking is 36-6. If it was a 37" 385 channel I believe it would be a 3690 but you only list spring tensions as high as 3670. Please advise.
Thanks & Blessings,
Joe