Classic Auto Air Belt alignment fix

My '69 factory compressor used one belt. But it had two idler pulleys just below it to increase the belt wrap around the compressor and crank pulleys. The two idler pulleys sort of squeezed it from both sides if you will. The one belt went from crank to compressor nothing else.

One belt driving both compressor and alternator I think is an issue because the belt around the compressor does not have much wrap much contact. Thats probably why two belts are needed with that setup.