Non tilt channel balance is not an even inch
A quick learner from USA says:
June 20, 2016
Looking for replacement springs non tilt 5/8 channel. piece measures 28.5 L x 9/16 w x 5/8 deep appears to look like series 351 or 390 and is 1/2 in longer than your sizes listed. I need 8 pieces for 4 windows
Tom from SWISCO responded:
June 22, 2016
Hello! With a channel length if 28-1/2", your part will need to be custom made. This shouldn't be an issue, as we do see this from time to time. Can you tell me how many you need? Once we have that, we can send you a custom product and price quote that you can use to place your order.