Its done been done. Was called the "Kiddie Hawk" That I know of, only one was converted, could be wrong.
Charles
Here is a link to the aircraft with the modified low tail, and its got 160 horse's as well. Its actually for sale, but you may have to get the nose leg fixed - or perhaps you could add to the list of Mod's and turn it into a taildragger
http://www.pipertomahawk.com/forsale.htmCheers