Glixal ATMT1-009 GY6 50cc to 80cc Chinese Scooter Engine 47mm Cylinder Head Assy 64mm valve for 139QMB 139QMA Moped ATV Quad Go Kart (Non EGR Type) Valve Length-64mm Intake Valve Diameter- 18.5mm Exhaust Valve Diameter-16mm Combustion Chamber Diameter-47mm This a Non EGR Head, Does Not Have the EGR Port