It just hit me, those wheels are off an X20 Murray.
The schwinn would have had heavy duty 36 spoke wheel in chrome, or tuff wheels.
Bet you can sell the wheels for enough to get repro. Tuffs.
Had a tractor tread back tire, and scrambler front.
I had a sx1000 the same year. I expected a ,36/36 or that model.
Cool find.