Sash Balance & Guide Identification

I'd like to identify the proper replacement parts for my non-tilt aluminum window built by Florida Extruders in 2003. Enclosed are pix of the proper parts. I'm assuming the spring comes installed in the unit. I've enclosed a few pix...I figure the part number would be S380-29 for the balance, and 18036 for the top sash guide. The bottom sash weighs approx. 20 pounds. The current balancer has 28C USB stamped on it. Thanks for your attention! btw..does the balancer include a top sash guide with it?

Thanks for the reply! The bottom sash guide is 1" deep, so it corresponds to 15-005. The top sash guide is an inch and a quarter at its highest point, (about 1 and 3/4 inches if you include the supporting structure in the back)15/16th inch wide at the ears, 9/16" above the ears and at its deepest point just short of 3/4". I hope that helps.

Thanks for the reply! The top sash guide measures approximately 1 inch by 5/8 inch at the top, and an inch and a half from top to bottom. Below the thin cap is a top section 3/4 of an inch vertically and a 1/2 inch wide and 3/8 inch deep. Below is a less deep section with a bevel tapering to the bottom. That section is 3/4 inch vertically. That last section is 3/16 inch deep before the taper to 0, and 1/2 inch wide. The taper runs 3/8 of an inch. Both sections have holes for screw attachment.

If I order a pair of S380-29 channel balances with the 2840 option, I should be good to go, providing I get the proper top sash guides?