Shawn;
My '96 Ford 460 is NOT the same as the local auto parts stores are familier with. I asked for replacement belts last year, he asked for make, year, etc. Gave me one belt and said it would match. Got it home, pulled the "dog house" cover off and my engine has two belts.
Ended up taking them both off and to the auto store for a match.
My guess is that the local auto parts supply stores will not be able to match your items up correctly. They will cross ref it with a pick-up truck engine.
I would try to contact Winnebago directly via a phone call. Sorry I don't have the number with me at this time, but I'm sure someone will be able to furnish it or have better advice today.
Good luck & let us know how you make out.