I have a 1996 Dodge ram 2500 cargo van with a 3.9l. While replacing the timing chain I decided to dump the ac since it never worked and I never intend to fix it. I left out the compressor and I bought the serpentine belt for no ac and discovered that the belt would rub between the water pump pulley and the idler pulley as they were now too close. Did non ac engines use a smaller idler pulley or a completely different aluminum bracket that holds the alternator, idler etc?

 

The easiest and cheapest way is to install one of these in place of the compressor and use your original belt.
https://www.stockwiseauto.com/dorman...=all&Model=all