I believe the cab itself is the same as the smaller trucks. Things like fenders, grill, running boards and hoods are upsized for the big rigs. It wouldn't surprise me to find that the basic cab from a pickup or a 1 1/2 ton, etc. might interchange, or at least be adaptable.
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
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