@bloo, these are the spec's from the 1983 catalog. It looks like the front was Sugino, with 39 and 48 tooth sprockets, while the rear was Sun Tour AG, 14, 17, 22, 27 and 38 teeth. Notice the Sidewinder and the Sierra have the same gearing.
@Oilit thank you! I had been wondering if it could have been a freehub instead of a freewheel since the smallest cog in the pics looks really small, maybe too small to be on a freewheel in 1983. It must be an optical illusion. My 81 Raceline had an early Shimano freehub originally (unusual for the time) and I wondered if that was what I was looking at on this 83 Schwinn. The freehub was really fragile and I replaced it with a Suntour freewheel, I'd have to look but it's probably the same 14-38.
You've got that bike looking good! Can you post a picture of the bottom bracket area? From the serial the frame was probably built in Chicago, but March 1983 was close to the end. And what's the head badge number, if you don't mind? My guess is that this was also assembled in Chicago, but the frame could have been shipped to Tennessee for assembly. Information on Schwinn operations during this time is pretty scant.