Tim, et al.,
Yes, even having the original part numbers and lengths may not ensure that you can get the correct belt the first time for an older piece of equipment. Especially if the pulleys may not be all original. I just ran into this last night when I tried to buy a new fan belt for my 68 Corvette. My research on the internet indicated that I needed a Gates 7530; the counterman at my FLAPS claimed the books said I needed a 7535. Luckily, I had the car in the parking lot and I showed him that his choice was too long. I had similar problems recently with my 261 with an alternator. Do your homework, have patience, don't give in or up, don't get too mad at the counterman if he has problems with an engine that nay be twenty years older than he (or she).
Hoyt
