The 2975 Victor Jr. is a good manifold for a 400 with good heads. Your power band should be right were the Victor makes power. You could look into the Weiand Team G series too. These intakes have slightly less plenum volume then the Victor and Super Victor. You might not have to rev your 400 quite so high. Plus the smaller plenum volume could help make more power down low for the launch, without sacrificing top end. Of course with a 400, your going to have nice mid range anyway. Just a thought....
