Thad, I have a 45 2 ton Chevy. The vehicle data plate does not match the actual wheel base on my truck but the gross is 13,500 lbs. The 2 ton has larger front king pins and beam axle.The 6400 has king pins that measure about 1-1/8 inches and the beam axle is 2-3/8 wide, the flange is 7/16 inch thick.The 4400 king pins are about 15/16 inch diameter and the axle flange is only 5/16 inch.The spindle has a metal cap sealing off the king pin you can easily measure that. I believe the 2 ton has larger front hubs with a 5 bolt bearing cover.
