Bummer. I'm really sorry to hear about this. I am running the Felpro head gaskets. This is my second C with them. Also ran an aluminum head 427mr with them which is a notorious problem setup. No problem with any of them.
I'm afraid that you likely have a cracked or porous head. I know how to mag the iron heads for cracks but I don't know how to do the alloy heads.
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