on my 305, and I put two push in breathers on the valve covers. Now using my brain, I realize that air needs to go in and out, not just in. My question is, can the air flow in and out or just in? I have edelbrock 4443 push breathers on both valve covers, and the carb started smoking and I had a bad oil leak from the valve covers shortly after putting them on. If this is a bad thing to do, does it damage the engine? When I bought the car it had only one breather and the other valve cover had the open hole. Thanks to anyone who knows the answer to this.