Single alt belt to two belt question

I know all about matched belts, I used to sell them. In a previous life I worked for the largest auto parts/ industrial supply store here in town. We carried all sorts of belts and sheaves, bearings and sprockets for the lumber mills and the Silver Valley mines.

Bear in mind that the 70 RR I mentioned I used to drive HARD. It did not tear up belts. I will admit that the AC being "hang on" means that belt did not drive other components, so it had a nice big wrap around the pulleys