Do the civilian trucks use both left and right hand threaded studs? If so, you may need to broaden your quest to four different part numbers. Do you have a Fleetpride store near you? If so, I would take a few samples over to them and spend some time searching through bins. I also agree with JRMunn; often the part number search ability is limited even though there are other equivalents available. Perhaps similar era Fords, Dodges, or Studebakers used the same studs.