I ran 2 600 CFM Edelbrock competion series on an Offenhouser dual quad low riser for all of 2 months. That's how long it took me to get fed up with the setup. Stand on it and the cars shadow would be a block away before the engine could catch up. Miserable gas milage,very poor low rpm performance. Looked nice but driveablity sucked. I went the whole gamot, jets , accellerator pump mods, velocity stacks, etc, etc, etc. Just bolting on a good dual or single plane made all the difference in the world.