If you want to hotrod a Ryobi, I would strongly suggest you do so on a twin ring version. I have both the old single and the new twin. Even though the conrod in the new engine is still the same stamped steel affair, Ryobi beefed it up quite a bit with wider webbing on it. The counter weight is made of a stack of steel plates riveted together - not exactly confidence inspiring.

I did run a single ring Ryobi with Bowman ring on glow fuel for a while. On 15% nitro, it will spin an 18x8 clear past 8500rpm. I chickened out and never lean the needle all the way - only pinched the fuel line briefly to see the tach jump past 8500rpm. Maybe The Ryobi is strong enough to handle the extra power, then again maybe not. Terry told me the same thing about the Ryobi. When a guy like him gives me advice like that, I take it very seriously.

BTW, I got some gasket material from Tower, and it's quite a bit thinner than the original Ryobi head gasket. I'd imagine any type of automotive gasket material should work fine too. Hi-temp RTV also works good.