TrinidadLR4
Full Access Member
There are far more tire size choices in the 20in diameter than 19, as you probably found. 275 55 20 comes to mind, that one is 31.9 Whatever size you end up with, make sure the load rating is sufficient for these heavy trucks. These tire threads are like oil threads, everyone has an opinion one way or the other. Generally i don't like rods and instead choose to mess with the heights via IID.