I'm not a Schwinn expert by any means but something looks off about this bike. Looks like a newer bike with some older parts thrown on. The geometry and seat stays seem off for an older bike, maybe I'm just seeing things. I don"t know.
http://phoenix.craigslist.org/evl/bik/2259386343.html
http://phoenix.craigslist.org/evl/bik/2259386343.html