IO-360 engine performance mods?/Going to Experimental Cert

[hewilson]

I expect, or hope really, to be in the market for a Skymaster later this year or early next year if I can get insured, a big "if." My wife would be much happier with me in a fixed gear aircraft and so I am thinking of a 336. Is anyone aware of any performance enhancement modifications available for the IO-360? Would appreciate any ideas or input. Thanks.