Heads for 440

Can't tell you a thing about the speedmaster heads. I can tell you I have 440 sources,Edelbrock,and trick flow heads and they are all an improvement over the stock Mopar castings.

Figure out what your budget is and go from there. A black Friday sale may get you in the door but I would at least have a competent shop check the heads out and make sure the decks are flat as well. You can always run a thicker head gasket if needed for compression issues.