For more information on this topic, I contacted James Wagner, the Truck Carespondent for the Early ford V8 Club. here is what James had to say:-
"I dug out my well-worn (not by me) copy of the Canadian 1945 Ford Light & Heavy Trucks catalog (form number appears to be 501 but not clear).
On page 7 of this publication is a box at the bottom entitled: "9.00-20 Tire Option." In addition to showing a rear view of the chassis-cab model the following text appears:
"The 3-Ton 176-inch Wheelbase chassis is available with 9.00-20, 10-ply tires, front and rear at extra cost. Heavier, wider front axle has 62.26-inch tread and wider dual-ratio rear axle, 72.6-inch tread. Spacers are provided in front fenders and running boards to accommodate larger tire equipment. The option includes special driveline shafts and bearings, heavy-duty wheels and 6-stud hubs." Aside from the wheel stud count this seem to match the trucks you question.
Apparently these trucks with the "odd fitting" grilles mated up the the extended width fenders are unique to the 3 Ton Fords made in Canada.