Tractor folks: I located the 1953 test report by the U of Nebraska for the McCormick Super W-4. ( http://digitalcommons.unl.edu/tractormuseumlit/1005/ ) Is the Super W-4 different from a non-Super W-4? Roy New owner of a W-4 Roy Morgan 13033 Downey Mill Rd Lovettsville, VA 20180 k1lky at earthlink.net