Hy vikikng58, according to my parts book the "seal unit, rear wheel bearing" o.e.m. p/n is 3717672 = National 6696S. Just as a side note, years ago I went to buy rear wheel seals for my 59 Spartan 100, when the parts man brought the box out I opened it and compared it to my sample seal, the i.d. was smaller, I said to the partsman that the seal was wrong, he said that was the number listed in his book for that truck, he said did you look in the box for an instruction sheet. I looked in the seal box and sure enough there was a piece of paper in there, the instruction was to remove the factory wiper from the axle tube and install the new seal. The new seal was a "Scott" type of seal which does not rotate on the axle but is clamped to the axle tube by tight fitting rubber on the inner bore of the seal, the o.d. of the seal fits into the hub bore just like a standard seal, so the seal rotates internally, this type of seal is for oil lubricated bearings/hubs, the oil also lubricates the internal part of the seal, hope that helps
