Since there were no hits on shims, I went on-line and purchased a plastic shim sheet 10" x 20" that was .004". It was only $4.95!! I cut off a piece, punched holes and used a scissors to remove the excess. Installed the shim and it gave me .003" clearance, right where I wanted it within the specs (.001" - .006"). Another item crossed off the very long list!!! The rear end is mounted in place and the brakes are going on, when I can find the clips holding the emergency brake cables in the backing plate.