gzig5 said

Have you established specifically on which ports and where the leaks are? There are several possible reasons for leaks and you can't fix anything until the cause is identified. Need to start with straight, flat surfaces on both parts at a minimum. I can't remember the brand, but there are thick, layered metal gaskets that conform to irregularities and should band-aid any misalignment. Personally, I would start by correcting any irregular surfaces. If two metal parts are flat enough and have enough clamping force, you can get a gas-tight seal that will withstand hundreds of PSI, without using a gasket. Can't achieve that with the bolt pattern on an exhaust manifold but it will be a lot easier to seal if the faces are fully in contact.

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