it will be either on a par or worse. will definatly use more fuel than a HIF :/ i would definatly put a box in. even if its a diddy one and you get the shortest good manifold from maniflow it will be a huge improvement! comon, you cant build a beast like this and stick a swan neck on it!
Think i'll need a bigger fuel tank!
Maniflow do sell one that fits without mods. Think you've swung me though. Makes sense to do it properly really!