Just what are you wanting to do? Pull the motor or place the motor in a truck for transport? Or both?
If it's for just placing in a truck for transport. I've been thinking about one that would go into the receiver hitch. 2" box out to 3" round with id of 2" then 2" round up with a boom and either a cable winch or one of the cheap electric winches. Of course you could prolly use something like that to pull one to if you build it with a extendable boom.