Viking Window Balance

Need to replace a Viking window balance. The metal channel is exactly 27 inches long with a stamp of 2630FG at the base, with the letters BSI running perpendicular to it. The top connector has wings on each side. The bottom connector design matches some of the product description photos on your web site, but it measures 1 1/8" long. Thus, not exactly matching the web site descriptions. Photos are attached. Please provide the correct replacement part number. Thank you.