The whistling is created by one of the runners flowing more or less than the other runners around it. You can also get whistling from a poorly ported head where the flow from cylinder to cylinder isn't close to being equal. Unless you want to rework the manifold on a flow bench you will have to live with the whistle.
you think that is where it is coming from? it makes sense but if my head is stock and untouched, then the manifold is where the problem lies?
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