The main disadvantage using a box truck or open dovetail bed cabover truck is the height of the bed (40+ inches) which requires giant dovetails or long, often bifold, ramps. If one started with a front-wheel-drive chassis, however, one could use a standard landscape trailer (as low as 16 inch deck height) or box trailer for the bed with drop axles. Attached are the some pictures of an example of such a custom machine (only it has a carhauler bed instead of a landscape bed); this was listed on ebay and was built using a 1970's GM full-size front-wheel-drive drivetrain (like that used in the early 1970's GMC motor homes) and a 1939 Diamond T cab-over cab. It is 21 ft long, with a 16 ft bed. I think I would prefer a single 6000 lb axle ( bit farther back) to the dual axles. The only other FWD heavy drivetrain I can think of is the VW one used on some Winnebago motorhomes; does anyone else have any ideas? I also speculated that you could use a 4WD pickup cab and drivetrain, minus the rear driveshaft and axle. You would have to come up with somewhere to put the fuel tank (unless you used an old truck with the in-cab fuel tank). Please share your ideas for a mower-hauling hotrod.