Originally Posted by cdminter59
If you have you engine built for low end and mid range power then these two intakes are your best choice. Edelbrock Performer or Weiand Street Warrior.
I love the Street Warrior on my 327. It's a much newer design than the Performer or even the Performer EPS. And the rear vacuum port clears Holley float bowls.
That single plane manifold is hurting your power at RPMs up to 4500 or even higher. The problem is all 8 intake valves are exposed to each other. That means, for example, while piston #1 is half way down the intake stroke, cylinder #8's intake and exhaust valves are both open (during overlap). This means some of cylinder #8's exhaust gasses are sucked through the intake plenum and into cylinder #1. And this is repeated on every intake stroke of every cylinder. The larger the cam, the more the overlap, the bigger the problem -- at least at low-mid RPMs.