An apparatus for mixing intake air and exhaust gases of an internal combustion engine includes a chamber having an inlet to supply a stream of intake air, and a second inlet that receives an exhaust gas flow. The assembly comprises an overhung screen portion preferably having face perforation and outer edge serration for equalizing pressure and disorganizing shear layer vorticity, and thus disrupting vortex formation. Method steps include installing a body lift kit and lowering the airbox.