They just won't quit leaking! I'm on my third set now! The head sealing surface is straight, the valve covers are straight, I'm torquing them to specs, the surfaces are clean. I am using m6 bolts with 10mm heads. I can't figure out where they are leaking from, but this time its about a quart every five miles. I just purchased a mirror finish center cover.....and the o-rings for the allen head plugs in the middle. I put the new o-rings on, and no, the cover is not under the valve cover or anything like that. I don't know what it is. It filled up the entire spark plug valley in a matter of minutes of driving. Two mechanics have looked at it, and are clueless...... Anyone know? There are no visible cracks, and I can't see the leak. They are only leaking on the inside close to the valley....not a drop on the outsides.