CRAP! I'm smoking!

Ironmike - Assuming the intake is not bottoming on the front/rear rails of the block, have you tried attaching the intake manifold without gaskets using all intake bolts ( I know you had the corner bolts in before but I would put them all in)? I imagine if the intake side of the heads or intake were milled way too much, the intake might just "hang" on the intake bolts thus leaving a gap bigger than your compressed gasket thickness. Just another thought.