Take a look at the gasket maker here, as hot as my engine gets, it holds air compression and remain harden without melting away. I use it as my base cylinder gasket. I was thinking about using it on my head cylinder but it's currently not leaking air so I'm not going to mess with it.
Permatex/3 oz. (85 g.) tube high-temp red RTV silicone gasket (81160) | RTV Adhesive | AutoZone.com