In that case, I would just use the wheels you already have if they are still useable. Universal Tire has a 7.00-18 highway rib truck tire for $205, and a 7.50-18 mud tire for $233. They are also US made. https://www.universaltire.com/truck-and-military/truck.html?p=2


Some of my crap:
1963 C-30 flatbed dually 292/SM420
1965 C-10 LWB fleet 250/column shift 3 speed
1965 C-30 9' stepside 250/SM420/4.10 gears (my DD)

Website I made for my crap:
http://www.66submarine.com