On the stud between the threads and the knurling is a shelf that is the same diameter as the area of knurling. That shelf fits on the rotor side of the hub but is too large to fit through the other side. I ended up grinding down that shelf just enough so it would go through without eradicating the knurling. Lot of work, but finally got success. I know I had the correct studs because the same part number was listed by four different parts dealers. Some dealers also showed Raybestos studs, and pictures of those looked identical to what I had, so must be the correct part. Oh well, what is an older car without a little work?!