Can I ask why you would want to use those heads? I get close chamber heads raise compression, but close chamber heads don't flow as well, and that old of head would not have hardened seats.
My 56 331 truck engine had hardened seats right from the factory in 1956. I've found verified proof all over the internet. And I don't mean induction hardened, but sho nuff hardened inserts. It would not sprprise me if those heads had the same.