DennyW: This is very interesting to me and you certainly helped me understand how the PCV valve works. Thanks!

I have one of the aluminum, breather/PCV combos on one valve cover and a breather-only on the other. I didn't realize they had variable spring rates on PCV valves. I thought all were created equal. I have had too much cam (and thus not enough vacuum) on a multi-port injection unit and just installed a Comp 276 to help solve that problem. I noticed small amounts of oil in the intake runners and seeping out the vacuum ports when I would disconnect them. Any idea how to help solve this? I have figured it had something to do with "lack of ventilation" but didn't know how to resolve it without causing other problems. Can I measure how much resistance the PCV valve has and know if it is enough?

Thanks in advance...