Close, but no seegar!
The 16" wheels won't fit over his brake drums, and the tires would be way too short to replace those 8.25 X 20 tires he's got now. These are real truck tires and wheels, and any regular truck tire outfit should be able to do the mounting without any problems. He's just dealing with a passenger car tire shop, and they're afraid of a real truck.
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!