Sterndrive Engineering Replacement Lower Unit Mercruiser Alpha One Gen II CRReplacement Lower Unit for Mercruiser Alpha One Gen II. 1991-Present. - Counter Rotating For Counter Rotation Units Only; Will not replace 2.00 & 2.40 ratio units; Up to 300 HP; Uses the latest style speedometer fitting (OE#860382) will be required for a working speedometer; Item is subject to a 20% restocking fee (Boat Covers, Bimini Tops, Outdrives, Drop Ship Items and Special Order Parts)!**Year, Serial Number, and Horsepower are required to order. Please contact us with this information after you place your order otherwise processing will be delayed.