My 8.3 ISC is a lot different than the 5.9 truck.
I changed the belts on the Newmar shortly after we to the coach, because of their age, but kept the old one in my emergency pac.
On US 2 in the rest area west of Spokane we pulled in for rest and saw a coach setting with the rear engine compartment open. Being a mechanic with a tool box aboard, I asked if I could help. he showed me his broken belt. we compared it to my spare and it was a fit. Changed it out for him. and told him to pay it forward.
On the ISC in my coach, there isn't much that a belt can hit.
Yes my A/C has its own belt, but runs off a serpentine belt driven pulley.
