<!-- s:) --><img src="{SMILIES_PATH}/icon_smile.gif" alt=":)" title="Smile" /><!-- s:) --> I have a 77 serial 4501 471. Why does it have a super 77 frame ?I was told, that it was changed , or the serial plate was change , and that some of the last 77's off the line had super frames? I also was told this one was built in Charles City. What is the difference? Is there a place to find a build sheet on this tractor.  Thanks Mike