What do you tow with your B?

I was recently talking with a transmission mechanic who had just finished rebuilding a Dodge 4sp with OD transmission for a friend of mine. The transmission was trashed when the van was used to pull a sail boat several hundred miles. The mechanic told me that the OD on these transmissions are prone to failure when called upon to pull trailers. He recommended turning OD off when pulling anything other than a very small trailer and even then he recommended turning OD off on long inclines or traveling into strong headwinds. This is going to require slowing down, unless you want to spend a fortune on fuel.