Ivan, I have a TE20 that I put a TO20 starter on and it works fine. However, I seem to remember some discussion threads back a few months ago about potential problems with trying to interchange the T0 starter to the TE. It may have had to do with shimming the starter to get better clearance, but I"m not sure.
I just remember comments that it was possible. You might try a search on the TE20 starter and find the threads.