A while ago, I asked advise on this very forum on a Edelbrock Performer manifold compared to a Victor. The advise I was given was to use the dual-plane Performer because it should make more mid-range power and give up very little top-end power.
Here are the dyno results. Ready? Sure? Ok...
The Performer not only produced 30 less HP on the top end, it produced 50 (yes that's 5-0, not 1-5) less ft/lbs. maximum torque.
And it was not any more streetable.
For bigger FE's with ported heads, big valves, greater than 240-degree timing and greater than .600" lift, it seems that from a sample of one, the Victor is the manifold of choice.
Remember, this is a sample of one, but I thought it might be interesting for those on the fence. Plus, it LOOKS like a REAL motor.
Brian