That’s a nice truck! is the diameter of a 700-18 is about 32 inches? measure the tire and decide what diameter you want Then play with the numbers in a tire size calculator Many available online, for instance https://tiresize.com/calculator/
A 255/70R18 is about 32 inches tall and there are many options in that size -s
Those 700-18's are available from the likes of Coker tire with tubes and liners. A modern day equivalent are 8R19.5 but you will need to find the rims to go with it. No other rim fits over your rear drums. Nice truck.
Not sure when they started but they are 1 ton drrw only up thru 1972. I have a "49 with them & my boss (dealer principal) has a 72 C30 with them. 1973 they stated using 16.5 wheels.
BC 1960 Chevy C10 driver 261 T5 4.10 dana 44 power loc 1949 GMC 250 project in waiting 1960 C60 pasture art Retired GM dealer tech. 1980 - 2022
I I did a quick search, looks like the 7.00x18 is pretty rare. Coker has a reproduction Firestone in that size, but it's a car tire. If your truck is just a cruiser and not a worker, they should hold up fine. They also have STA and Deka tires. They're both a little pricey, $200-250 for the STA and over $300 for the Deka. Not to mention rim flaps and tubes.
BTW- the STA Traxion tires are actually more of a mud tire and not the one in the Coker picture.
