Size has to be so precise... This person would have to buy several and keep changing them if you don't have a size recommendation. I had a high output alternator installed which requires a .5" shorter belt...Needless to say even though i reminded the installer to get a shorter one, and he reassured me he would, he left factory one with 60k on...Fried the Alternator and caused slippage. Luckily alternator has a warranty. What is the downside of me not having a one way rotational decoupler pulley? Or OAD (Overide alternator decoupler) The high output alternator came with a smaller non OAD pulley. Does it matter if it is a whole new alternator regarding the fan blades rotating the wrong direction?This is not even remotely true. The only downside is routing without a/c requires changing alternator rotation. This is not entirely an issue thanks to dodge using a spring loaded decoupler instead of a one-way rotational decoupler pulley. It will work, but the fan blades on the alternator will be rotating the wrong direction so alternator cooling won’t be as efficient. That said, the 82.5” belt listed most places as the no a/c belt is a couple inches too short, you will need to go up a couple sizes.