Eric is right, the massive increase in exhaust flow will cause the engine to lean out. A bigger concern would be the cold air and the hot piston top. If you want to run open, use a legnth of pipe or tube attahced to the header to keep from warping the piston top. Unless the rest of the engine has been modified to take advantge of the flow it won't do much, if any, good and it will MURDER your low-end to mid-range torque.