Mercury - Quicksilver Complete Sterndrive Alpha Gen II Standard Rotation (RH) 2.00 Gear Ratio 51100007P. Overview. Built for boaters who want reliability and performance from a proven design, the Quicksilver 51100007P Complete MerCruiser Alpha Gen II Sterndrive is a direct replacement drive engineered to fit the legendary MerCruiser Alpha propulsion system. Designed for single installation 3.0L Alpha sterndrive engines up to 150 horsepower, it's ideal for runabouts and pontoon boats. With its Tr