I like to use brass nuts to draw up that flange to the manifold so the next time I want to get it apart its not twisted off studs again. Can also use brass jam nuts to keep them nice and snug. You sure it's at the donut and not between the manifold and the head ? This is a GM 350 and I had an exhaust leak. Planed the manifolds which eliminated the leak.
 (manifold.jpg)
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 manifold.jpg (80KB - 38 downloads)
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liquid muffler sealer? ?
