Burton Power performance cylinder heads are hand ported and engineered to the highest standards to give superior performance over a wide range of applications. All staged heads are supplied fitted with new valves, springs, retainers and cotters. Special requirements can be accommodated on any head, please contact us for details. All heads are priced on an exchange basis. Exchange units must be crack-free, in a serviceable condition and unmodified. Inlet valve 33.5mm/exhaust valve 30.0mm. Early hydraulic type head.