Possum I'm not a ton expert,had I think 2 in my fleet of 30 in about 50 years. Correct me if I'm wrong the ton trucks had a screw on hub cap (the little one about 2 1/2 inches) with a hex made on it maybe 8 flats. 3/4 ton had a drive on cap like a 3100 on the front hubs. I guess we'll see if oh47pickupman lands this one.