I took it apart and used a flashlight to check for gaps between the manifold and the heads. It looks like the angles are correct and the manifold looks like a good fit. I started looking for cracks and did not find any. However, the surface of the manifold where it contacts the heads has fairly deep milling marks. They may be the source of the soapy water air bubbles when I installed the manifold on dry gaskets. They may also be the reason I can hear air escaping on the bottom side of the manifold. It looks like I may have about 1,000 tiny air leaks because of the grooves. The depth of grooves are similar to a fine file.
