I think I am going to go this route:
http://cgi.ebay.com/Robin-Subaru-Eng...item45f2a980ec
Robin Subaru 9HP engine, 1" shaft. I will then just need a 1" bore Comet 30 driver clutch, right? From what I've read, these Robin engines are very under rated as far as power and torque. Will this give me a noticeable performance gain over the stock 6HP tecumseh?