Do you put silicone on head gasket?
Besides, do I need to put sealant on head gasket?
If you're installing one of those old school embossed steel gaskets, you need a sealer to cold seal the engine. But most modern gaskets do not need to be coated with any sealers. And if you're installing a coated gasket, avoid any chemical seals.
Also, can I use silicone as a gasket? A. That would be OK, you can also use instant gasket that is high temperature silicone at a push. Even normal bathroom silicone sealant is temperature resistant to about 250 degrees C. If the gap is too big between the pipe and slip-on can, try packing it with kitchen foil as well.
Also question is, do you put RTV on head gaskets?
NO!!! You don't ever want to use a sealant like rtv on a cyl head gasket. make sure your cyl head and block deck are smooth and clean and put the gasket on by itself. I use Copper Coat on my head gaskets and have for decades It also is great for intake/exhaust gasket sealing.
Do you put gasket sealer on both sides?
So no way would you ever need to use a gasket and sealer at the same time. Just a thin material to seal the scratches is all that is necessary. Too much sealer and you could get a leak. Just use a gasket and you will be good to go.