Oil pooling

Oil is pooling at the rear of my heads and eventually starts seeping out of the valve covers. Never did this before my head swap. Ever since I swapped to the pro comp heads, the oil stays in the back and pools until it starts leaking out above the spark plugs. When the valve cover is removed I can see the oil sitting there at the back. I took an old valve cover and cut it out so I could watch the oil. It sits there and puddles up and then eventually works it's way between the valve cover gaskets and heads. Could just be that my anodized valve covers won't seal with these new heads and intake. Anyone ever dealt with this type of scenario before? It's a 340 with the pro comp aluminum heads and pro comp air gap style intake.