Question about 4027596 heads...

Does anyone have this set of heads? I have just put on a Edelbrock 2176 and haven't seen these middle water galley on it like this on any heads before.... It appears that they are not for anything special, but I could be wrong. When you put the manifold on, it leaves a gap..

I am assuming that I would need a different intake, but everyone tells me that this is the right manifold for my 360...


Any help is greatly appreciated! (Don't know why, but click on the photo to see it... )