73-76 spindles

when I bought rotors, bearings, and seals from rockauto last winter, the bearings and everything fit right, BUUUT the seals didn't. the seal changed in the late 70's/early 80's to a larger OD, and the rotors I had ordered (labeled as proper for a 1976 duster) were machined to the larger seal diameter. I had to buy seals for an '85 5th avenue, and then everything went together just fine.