Spoke with Manafrey today...he said he has sold HUndreds and hasnt heard of anyone machining anything. Guessing it depends on whether or not the manifold is warped. willhave to wait and see....tyYes, the intake manifold needs milled, because it is warped.
Yes, the manifold and header ears will need machined to get them to the same thickness.
Or you could skip one or two of these steps, then complain about how the manifold gasket always leaks.