you know PVC valve on the left front of the 420a. i was thinking about it, and could you a breather type valve on the intake part, and just leave the other part there, or block it off of something like that?

i thought that it would look kinda cool to have a mini filter on the in. manifold.

Okay, if i am understanding your question right: You want to take the PVC valve off... Cap the Valve cover, and put a breather on the intake..
If that is correct. Don't do it. You will cause a vaccumn leak on the intake manifold side of the equation.
However, if i miss understood the question, and you want to put a breather on the valve cover, and cap the intake manny, then that is cool. Just you won't pass a smog check if you live in cali...
hope that helps..