intake milling

it's per .0048 milled from head=1cc, and for every .0048 off the head.. you need to remove .0095 from the intake face, be it heads intake face or the intake manifold itself.

so you're off .0364 a side wether it the heads or the block deck, 'or even how the intake was cast'

OR .047 considering you are .020 high still

The edelbrock manifolds are sand cast and have a loose tolerance for the flanges. I always cut the manifold instead of the intake face of the heads. The heads are too valuable to cut more than necessary. Good luck with your build!