The base wheel on 1953 1/2 ton was a 16x4.5.

But, the truck could have come from the factory with optional 15" wheels (RPO-273H 6-bolt 15x5.5 wheels). The tire was a 6.70x16. It looks like the same size tire was base equipment on 3600 trucks (8-bolt 15x5.5 wheels)

As Whitedog posted, the optional 15" wheels would not have come from the factory with 7.50 tires. I have run 7.50x15 Toyo radials on those RPO 15" 1/2 ton rims.