MECOA makes a conversion head for COX engines. I have several for my .049 and .15's. A few head gaskets will help set the compression ratio. Will not be a race ready set up but for every day fun they work. For the .09.
911-046 MECOA Plug adapter for Cox Tee Dee & Medallion .09
The K&B 1L 7311 works great in this adapter
The price $13.99 plus shipping.
