This is going to take a minute, so I will get to the point. I have a 388 stroker with about 1000 miles on it. I just finished building it before the winter. I had Edelbrock valve covers on it and they were in pretty bad shape, so when I got the money I bought new Aluminum valve covers. I had a K&N style air breather (open filter style air breather) and never had a problem with it when the Edelbrock valve covers were on. When I put the Aluminum valve covers on, oil would come out of the air breather and leak onto the valve covers. I put the old air breather I had back on (just a Mr. Gasket air breather with a limited hole and closed face, pretty generic) and it seemed to solve my problem.

However, I still seemed to be losing oil. I checked underneath to see if I could see oil leaking from anywhere, including a bad seal on the new valve covers, and to my displeasure, I noticed oil leaking from the back of the oil pan where the main seal is. I am not exactly sure if it leaked from there all the time even when I had my Edelbrock covers on, or if it was just when I had the aluminum ones on. I just think that the aluminum valve covers were causing too much pressure build up in the crank and causing it to clog the air breather, thus making oil spew out in whatever point it could. The PCV valve seems to have good negative pressure (suction), and I even backed it out a little bit in case it was too close to the baffle of the aluminum valve cover.

So, I went to put the Edelbrock valve covers back on to see if it stopped the leaks due to better breathing, and to my displeasure even more, the washer (or retainers, im not exactly sure) underneath the bolt for the rocker arms, I found that 3 of them were cracked. So the car is sitting and I am not using it until I get that fixed, but does anyone have any suggestions as to what could have been causing the oil leaks? Do you think it was the valve covers causing too much pressure? The gasket for the oil pan is a really good one and the main seal is brand new (2 piece). Anyone ever have a problem like this? Any suggestions?