Breather and valve covers question
I would absolutely NOT close off one side. At very high RPM, the engine may well have more blowby than the PCV can handle. This is precisely the reason the factory ones were connected to the air cleaner housing -- and is the way it should be done.
What I use on my "old" aluminum covers is a big breather / filler off a Fraud. 70's Mustang/ Galaxie, Etc 390 etc etc. It's a big breather that fits the "twist in" filler spot, has a grommet in the top, and breather filter material to keep oil from throwing out.
Like this, only I found one, years ago, that was chromed:
Hey, it's an original:
I would absolutely NOT close off one side. At very high RPM, the engine may well have more blowby than the PCV can handle. This is precisely the reason the factory ones were connected to the air cleaner housing -- and is the way it should be done.
What I use on my "old" aluminum covers is a big breather / filler off a Fraud. 70's Mustang/ Galaxie, Etc 390 etc etc. It's a big breather that fits the "twist in" filler spot, has a grommet in the top, and breather filter material to keep oil from throwing out.
Like this, only I found one, years ago, that was chromed:
Hey, it's an original: