[tubman]

Here's what the owners manual says. In 1951, the "DeLuxe" (base) models came with 6.00 X 16 tires. Note the significantly higher pressure they call for. It's on the bottom of the right hand page. For those of you who don't want to strain your eyes or neck, it says :

...Size...Front Rear

6.70 X 15 24 21
6.00 X 16 28 25
7.10 X 15 25 30

(I believe the 7.10 X 15's were used on station wagons, thus the higher rear pressure.