Gil,
A .049 Medallion should do well on this airplane. It is not as powerful as some later .061 engines, but it is nice and light. Medallion engines are very friendly when compared to a TD. The TD .049 engines are great competition engines, but they prefer a pressure fuel system. I like my Medallion .049, it is easy to start, easy to needle, and runs great on suction fuel feed.
Thanks, Pat