alternator pulleys

I understand there are two designs of the C5AF-10A352-H pulley. One has the stamping fairly close (perhaps a tad over 1/8" away) to the center hub step-down and the other about 5/16" away. Whenever I see the back side of the pulleys with the close stamping, it has an outer perimeter of about 3/16", then the pulley steps down slightly until the step up at the hub. I don't believe I have seen a picture of the back side of the one with the stamping about 5/16" away. I have two of these pulleys that are supposed to be originals and have sufficient groove wear in the steel to suggest they are originals. The back side is flat with no stepdown. There is a step up at the hub. Both weigh within one-half ounce of each other (1 lb. 13.5 oz.). Anyone come across this style pulley?