Brian Crower Intake/Exhaust Valve Set for SR20DET These Brian Crower intake and exhaust valves are made from premium stainless steel, fully machined and swirl polished for ultimate air flow. Dished head for added weight savings and increased valve control at high rpm. Standard and oversize head sizes available. These are stock sized 6mm intake and 7mm exhaust stems. Please contact us if you would like an oversized valve