Unfortunately there isn't much you can do.
You may be able to use two header gaskets on each side to give you enough crush area to seal.
The problem is really the header flanges themselves.
They get hot enough to warp themselves away from the heads.
Don't bother with the high temp silicone.
You will just make a mess and get it all over the tubes and engine.
If you find a sure fix, please let me know too.
Good luck.
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