Volvo Penta AQ 171 B230 4 Cylinder Engine DOHC Wet Exhaust Manifold 855434. In excellent condition with no cracks. Only fits DOHC with oval ports. Obsolete and very hard to find. Has a broken thread flange for the heat exchanger brace mount. Can be ended or used as is. Was like this for many years and performed fine. Fresh water use.