If you're planning to run a flat bed in the rear, the track width of a dually axle will be less of an issue than if you're running fenders. Up front, a little creative metal butchery can widen the fenders a couple of inches by splitting the fender and grafting in a piece of sheet metal between the headlight and the outer edge of the fender. It takes a pretty sharp eye to tell the difference if your body man knows his stuff.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!