?? RHS or edelbrock heads for my 408 ??

A lot of that was some people confuse the "better head" with the "better value." Yeah, you'll be able to make more power with Eddy, but unless you're trying to make more power than RHS is capable of, the RHS heads are the better VALUE (HP per $). When you have someone asking "Which heads, RHS or Eddy?" and their post goes on to say they want a 450 HP street motor, then RHS would definitely be the way to go at barely over half the price of Eddy's. If someone was going for something over 550, then Eddy's would probably be the better way to go. Neither RHS or Eddy are the best head out there.
I have ported eddys on my roller 340 pulling 450 hp rite now. Im looking for another 100hp. Shadys 408 in my buddys duster has eddys and thats pulling 550. Im thinking the eddys will be a better choise so i can run a little more compression. Not worried about the port work. Good buddy of mine owns a machine shop. He treats me well. What kind of flow #s should i be looking for to get 525-550 HP?