1965 Dodge Dart 273 with A.C. Pulley Questions

I think the '65 V8s had two belts and '66 V8s had a single belt- could have been a mid-year '65 change at some point.
I think the '66 version with one belt & TWO pulleys (a tensioner & an idler) offers better or more belt "wrap" around the AC compressor pulley and also the alternator which would explain the revision.
For pics see here:
1965 vs 1966 273 AC accessory drive