Ok great, are these pretty easy to change? Do you happen to know the touqe?

This might be a dumb question but, you would'nt leak oil out of the head gasket would you? It would be just antifreeze if it were to be leaking not? It just seems really oily there.

also Im changing out my coupler, do I need to get a gasket for that or just leave the old gaket on and use rtv silicone?