[ceslaw]

I believe the problem has been discovered. Covincor, you absolutely nailed it. Special thanks for so perfectly identifying the problem. As soon as I read you post, Ryan and I headed out the garage to check it out.

Upon pulling the valve cover and carefully looking at the intake manifold gasket, we discovered that the portion around intake runner #2 was moved outward about a quarter inch. The impression from where it had originally been placed was visible. What appears to be a rip in the gasket is visible on one side. The gasket holes are not centered on the manifold bolts. So it looks like we will be replacing the gasket.

I have posted pictures at the GT40s.com site, Engine forum, thread bearing the same name as this one.

Any ideas why the gasket would fail?

Replacing the gasket would seem fairly straight forward, albeit time consuming. Any tips or recommendations would be welcomed. Guess I will NOT be using Felpro but will try the Victor Nitroseals per your suggestion.

Thanks to all for the good analysis and tips and suggestions. Without this forum I would be really lost.

Chuck