When you say disassembled, what do you mean?
I towed a 54 3804 some 200+ miles with a 16 foot bobcat trailer and my F150. It was a little tongue heavy, but I had a set of tires, tools, come along, jacks, chains, air tank, etc... in the bed. A longer trailer would've let me roll the truck a little further back on the trailer and get some of the items out of the bed.
Your best bet may be a Uhaul box van and a flatbed trailer. You'll have to take a tape measure with you though, since the 3800 has a 137" wheel base. The Uhaul trailers are fairly short.
Another option is a company that hauls RV's and trailers. You may be able to catch one on a dead head.
