I would recommend having your machinist check your intake and retrue as required, heck I'd have him true it just because you don't want to find a leak after you've got it all back together. It looks like a vacuum leak to me. How did your plugs look? If you were having trouble with low vacuum at idle, and fouling plugs you found your culprit!
Intake; I used the Felpro 1256 intake gasket it was the correct size for my 472 intake runners its grey and looks close to an original. I also used the Intake Manifold Gasket Alignment Tool posted over at Camaros.net.
Post for intake tool here: http://www.camaros.net/forums/showthread.php?t=121095&highlight=Intake+Manifold+Gasket+Alignment+Tool
Use Permatex Aviation Form-A-Gasket Sealant Liquid at your intake runners, it won't be effected by fuel or heat and will ensure a lasting seal.