One word of warning... From what I have determined on other forums Workhorse, or rather GM, who made the engine, used TWO DIFFERENT belts on that engine, One is longer,, Do your very best to get the number off the belt.
Mine came from NAPPA by the way. (Just put a new on on last month).
Time to cut the remains of 1/2 of the old one off the fan (Lying on my back under the motor home) about 1-2 hours.
Time to replace the belt (Professional job parked over a lub-pit) 30 minutes.