The MARK ONE sets the standard........headsheet to tailgate.

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The Mark One is the result of an ongoing quest at Henderson Manufacturing to provide the trucking industry with innovative products that exceed expectations. Its streamline styling is just a clue to the attention that has been given to every detail of design and manufacture...because "form follows function". An axiom the Mark One's design team has held to ....tenaciously.
....The Mark One innovations start at the truck's frame and reach right up over the cab. There's no skimping on quality anywhere. Some of the features you'll notice immediately are the absence of cross-members along with a 3/16" one-piece floor to eliminate washboarding, a unique hoist that cuts the size of the doghouse by two-thirds (XD and SD models), dirt-shedding braces and top rails, cab release air tailgate, built-in clearance lights with auxiliary stop/turn/tail as part of the light package, and a score of others. It all adds up to a more durable body at reduced weight with increased payload.
....And there are options. Lots of them! With some pretty original thinking here, too. The Mark One is available in three models, each in six different lengths from 13' to 18' with each size available in 36" and 44" side heights to satisfy a never-ending list of applications. But there's more. An asphalt delivery version is also available.