I have Dougs and had no leaking problems for a long time, then all of the sudden, I keep blowing gaskets. Next set of gaskets I'm getting are the ones that come with the headers because they are about twice as thick as regular gaskets, and I'll run a small bead of the copper gasket sealer around them. I've done that in the past with good results, but haven't used it lately. Only problem with that is that if you need to take one off for some reason, there's no chance of being able to reuse it.