I thought that these manifolds would be brought up, noticed their rpm range, 2,500-6,500. Both have big runner's and port openings. Most on here say that the edelbrock performer isn't more than a factory intake manifold. I'd like to see a manifold that would have good throttle response and low to midrange torque.
Do you have any real world experience with these engines and their characteristics? If you aren't getting what you are speaking of with what's available either quit trying to be an engine builder/tuner or find a new builder/tuner.