Current stamp is stronger than sash weight
A home owner from San Clemente says:
July 3, 2015
Paul from SWISCO responded:
July 7, 2015
Your original stamp, "32 5," corresponds to our 3250, but that appears to be too strong compared to your sash weight. Did you ever find your window to be difficult to operate in the past? I'm not sure why the original installers used a stronger spring, since there is no benefit.
Double check the weight of your sash, just in case. If it is, in fact, 26 pounds, then I would suggest the 3240.