1980 Ford F700 enclosed race car hauler on ebay.

[BravestDog]

Take a look at the size of the cabover. Looks like it might break off if you were to overload it.

http://cgi.ebay.com/ebaymotors/1980-F-700-26-FT-ENCLOSE...QQrdZ1QQcmdZViewItem

 

[Gary Atsma]

Looks like an ex-moving van. Movers USUALLY put lighter stuff in the cabover, but that's not even the bad part; it has a GAS engine in it, a 429 no less. I estimate approx. 5mpg tops, with a tailwind.