S380-34 stamp question

A professional from Naperville, IL says:
May 25, 2016
This is the balance and top/bottom clip set i need. I only need 1 pair for one bottom sash on a non-tilt single hung. I weighed the sash and it was 40lbs, and there is no stamp on the old damaged balance. Do i need to get a certain stamp or just order normal?
Profile picture of Tom
Tom from SWISCO responded:
May 27, 2016
Hello! You would need a custom balance. I'm thinking of the 3370 option, which can carry 39 through 42 pounds. Would that work? I'll send you a custom order link for two of these that you can add to your cart.
34" Series 380 Channel Balance
34" Series 380 Channel Balance
S380-34
$11.73
How to Replace a Non-Tilt Channel Balance
How to Replace a Non-Tilt Channel Balance
VIDEO
WATCH >
How to Repair a Jammed Window
How to Repair a Jammed Window
VIDEO
WATCH >
How to Identify Replacement Channel Balances
How to Identify Replacement Channel Balances
VIDEO
WATCH >
How to replace a non-tilt channel balance
How to replace a non-tilt channel balance
GUIDE
READ >
Choosing a Non-tilt Channel Balance: What Will We Need?
Choosing a Non-tilt Channel Balance: What Will We Need?
GUIDE
READ >
Reply to Thread
Use this form to ask a follow-up question or to share your experience regarding this subject.
(your email address will be kept private and is only used to inform you when a response has been made)
Current wait time is 3-4 business days
We promise that one of our experts will personally get back to you as soon as they are able. Thank you very much for your patience and understanding. If your inquiry is time-sensitive, please feel free to reach us at (888) 991-1929 or at help@swisco.com.