Before the MLS gaskets came about, everyone used copper head gaskets and O-rings in either the block or head deck surface. That was the only way to seal them up when the composite type gaskets would blow out from too much cylinder pressure...whether it be from boost, nitrous, or just high compression.
If at all possible, I'd run an MLS gasket. Remove the wire from the grooves and either mill the heads flat again, fill the grooves w/ some epoxy, or possibly just leave the grooves in place if they don't interfere w/ anything.
Copper gaskets are a PITA.