I just fired mine up while it was stone cold in the garage.
I have zero vacuum on the valve cover. I checked by placing a piece of flat paper over the opening. You must have a problem. At least, with that vacuum, you probably have no top end leaks.
BTW, mine is a '92 SSE that will turn 200K in about 100 miles. I burn no oil; also, just installed a new pcv last week. The old one had 30,000 miles on her and looked as clean as the new one. I've never seen that before, but I checked and the system was creating strong vacuum through the old pcv so I guess my system is running very clean.