My 1958 model 3800 dually has 8R19.5 rims. They are one piece tubeless wheels. The build sheet inside the dash shows that this was an available option for this year. They are 8 lug hub piloted rims. They are riveted rims to centers, and have KH (Kelsey Hayes I think) stamped on them by the valve stem hole. I have every reason to believe these are original to this truck.
The hub pilot diameter is smaller than more modern hub piloted 8R19.5's. The lug diameter is smaller than more modern lug diameters.
I've not seen any "off the shelf" 19.5 rims that would fit on this truck in the same fashion (and I'd love to have a spare!). I'm thinking the "eaton" rear axle of 3/4 and 1 tons from ... not sure early on to 1972 will all use the same hub pilot diameter and lug diameter.
