Edelbrock 1406 whistling

These intakes are made for multipurpose carb use. That is why the carb flange is so thin. Not all castings come out the same. yes the machined surface looks close between all of them but the width of the flange differs. I have seen strip dominators with the same issues. It is more convenient for the manufacture to make all of the intakes the same and offer a plate,this allows them to make these intakes with the same flanges for different carbs. This also alows for greater tolerances of the width of the flange for QC. This is the nature of these intakes its always been and always will be. They are cheap multipurpose intakes. and is the reason for all of the different holes they come with. The better intakes you usually need to drill a hole if you need one, or have the flange machined or die ground for fittment. But the better intakes are for those who know how and have the equipment to do so. A piece of wood is a good straight edge for wood working, spreading puddy, or a butcher block, but not for metal. all machinist cringe when they here this. The house hold item to use is a piece of milled marble or granite cut out of an old counter or sink, or just a thick piece of glass. The proper tool is a machined ground straight edge and a feelers guage. the quickest is a piece of paper between the two surfaces being mated. The best is a quick cut for straightness on a surface grinder. After this said i am sure he will find his problem with some help. And when he does he will, or all of us will be asking ourselves why didn't he or we think of that. Isn't it always the case , what is wrong is always staring us in the face and we never see it because its to easy.