try Cometic head gaskets. I would order them from Keith Craft
FORD FORD BIG BLOCK FE Cometic Head Gaskets - Free Shipping on Orders Over $99 at Summit Racing
I have great success with Percy's laminated aluminum header gaskets. They work when copper, Fel Pro, Mr. Gasket and many others failed.
They are the only header gasket I will use. Sometimes my flanges are so warped that I have to use one and half Percy's gasket.
But they hold!
I don't know if Percy's make one that will fit you heads but you need to check them out.
Percy's 66053 Header Gaskets Aluminum Ford FE 332 428 Rectangle Port | eBay