If you use the complete front end from a big bolt, fenders, grill, radiator support, etc, the fenders will be about the right width. You might have to do a little cosmetic surgery on the wheel openings, since they were intended to clear 20" rims with bigger tires than the chassis you're working with. Another approach would be to split the 1/2 ton fenders lengthwise and graft in a 2" wide extension on each side to widen the original front fenders.
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!