Mercruiser Lower Unit Alpha I 1623-8951A43, NewFits: Mercruiser Alpha 1 lower unit for sterndrive engines 1984-1990, New, 3 year fault free warranty OEM # 1623-8951A43 Add applicable core chargePrice = $1,195.00Call 913-342-0011 for assistance. Please have your engine serial number available if possible.