Olli, I don't think I explained myself very clear in my post.
I like the FunnelWeb and would try one, but I believe at this time they are only avaiable for the 302 and 351 cleveland. I used the FunnelWeb as an example of a "tall single plane manifold" since it is the only one I can find HP comparisson charts and flow data on. My theory is that the Victor and SuperVictor manifolds should be similar to flow ratings of the FunnelWeb.
More proof that the fear of tall manifolds may be overblown is a simple test in dyno2000 with an engine fitted with a dual plane, single plane, and then monster tall tunnel ram. Let me whip one up.
Here is the ford 351 crate with a dual plane, single plane, and tunnel ram. It is a little hard to see the lines since the single plane and tunnel ram basically match on the TQ and HP curve.
http://www.cobralads.com/dyno2000/351_tri.gif
the peak numbers are
DUAL
HP 379 @ 5500
TQ 412 @ 4000
SINGLE
HP 401 @ 5500
TQ 421 @ 4500
TUNNEL
HP 401 @ 5500
TQ 420 @ 4500
so the truth if the matter is that "yes' you lose bottom end and at 2000 rpm, the dual is about 50 TQ higher. What most people fail to realize is that you gain higher peak on both HP and TQ. when going to a single plane. Generally higher produces more peak HP but in this test, it did not. For racing, single plane is the way to go and I don't think there is much penalty going for a victor (except in the pocketbook). For a street cobra running running at low rpm, then the dual will give you that low rpm kick in the pants.
In many dyno tests, adding a simple 1" spacer improves HP. I believe running a 1" taller manifold will do at least as well as the spacer since the runners are taller the entire distance. opefully some of the magazines will start to do these tests in the future.
Andy