Just got my fan clutch back from being restored.  This is the Eaton fan clutch, that was used on 65-68 chevelles with a BB and the short water pump. Used in the K02 option or the C60 air conditioning option. Different from the SB fan clutch in that the mounting height was 1.5" instead of the 1.7 mounting height for the SB.  Also the face is different then the face in the later NOS fan clutches.  

If anyone is interested in the contact information for the guy that restores clutches, let me know.