Dyno a 7.5:1 400? Sure, why not?

I kinda like the standard 440 Source heads and a lot of people run them OOTB. But I think they need a lot of prep work. For another option in lower priced aluminum heads you could look into these.

mopartsracing - Sidewinder Cylinder Heads For Big Block Mopar

Wow that sounds almost too good to be true! But thanks, I'll look into that!