Thank you for doing this video! I just had the same exact problem with the same exact van. Advanced auto said I have a 130v altinater the smaller belt is for 105v. This really saved me a lot of headache.
Advanced didn't ask me alternator size so I ended up fighting with the short one for an hour and googling for an hour to find this. Short bus is about to be back on the road 😄
I have a 3500 short bus and the tensioner is on top while the idler is i On the side below the alternator. Idk if its right or if somebody did that to make it easier to change