set of Bloomer heads( I would call Rod Bloomer and see if he has some available) would easily get you there with an optimized combo.
know of two such builds that have already well exceeded the 600 figure.
that way you can use production style intake, rockers, headers etc that are available.
Question. Do the Victor heads use the factory standard manifold ports and bolt spacing. I thought that they did and fit once the spacers were in place?