[fiveohpatrol]

You will have zero vacuum with the engine off.

Sounds like you need to take your lower manifold to a machineshop and have them mill it some. What I would do is, clean everything really well, leave it dry (no RTV), put the lower intake on and torque it properly. Then take a set of feeler gages and measure the gap between the block and the intake. Tell the machineshop what the gap is, and if they have anyone there that knows anything about geometry, then they can figure out how much to mill off.

Hope this helps, good luck

-drew