I had a leaky exhaust manifold gasket and a cracked expansion bellows, (the corrogated steel piece between the front and back exhaust manifold on the six's) I replaced the manifold gasket and enpansion bellows but the leak came back. whenI did the head I had the exhaust manifold shaved since it was severly warped from the exhaust gas heating it up differentially.
Never had a leak on my non-turbo cast iron heads.

henry

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