Gasket(s) installation

I installed a Felpro rubber gasket on my valve cover with some RTV silicone (I know, it says not recommended for rubber gaskets) and she leaked from every single bolt hole. I have heard about soaking cork gaskets in water overnight and installing them without any sealant; does this work for valve covers? I also need to change my carb-to-spacer gasket and possibly my spacer-to-instake gasket, how do you recommend I do this?

Thank you to some of you who took the extra time to answer some of my questions via private message and email. I pulled the PCV value and as I was looking I noticed the elbow was cracked. I replaced it and it no longer has symptoms of a vacuum leak.

However, the valve cover is still leaking from one bolt hole, where it is obvious the previous owner over-torqued the bolt. It had pushed the bolt hole downward, creating a thin crack. I attempted to straighten the bolt hole out, but it didn’t stop the leak. I am afraid the oil is leaking into the sparkplug hole. Btw here is what my valve cover looks like.



The other thing that I have noticed is that neither the rubber or the cork gasket seems to fit the valve cover or head correctly. I have been told that all "small" inlines (144, 170, 200, 250) have the same gaskets. So I get Felpro gaskets for a '65 200, despite the fact that I have a '78 250 and '80 Head.