here's a few pics of the 720, the 670 and the 580 engine. The 670 wasnt finished in these pics though.
http://pg.photos.yahoo.com/ph/polaris_400_2_stroke/album?.dir=4447&.src=ph&store=&prodid=&.done=http%3a//pg.photos.yahoo.com/ph/polaris_400_2_stroke/my_photos