Are you running open headers or with a exhaust system.. if running a exhaust system take the evacs out(both sides) and run open breathers or 1 breather and a PCV Also try blowing thru the breather to see if you can.. I have a pair of breathers on my 416 and I couldnt blow thru them and had to pull some of the material out of them.. you should be able to blow thru them easy and blow thru them from the engine side(the way the air would be going)