Mercury - Quicksilver 815822A53 Complete Standard Rotation (RH) Gearcase Alpha One Gen II Sterndrives 1.47-1.94 Gear Ratios 815822A53. Overview. Your Alpha One Gen II drive is built for performance, and when it's time for a replacement, the Quicksilver 815822A53 Standard Rotation (Right-Hand) Gearcase gives you the same power, smoothness, and reliability that Mercury designed into the original.. Built for MerCruiser and Quicksilver Alpha One Gen II sterndrives with 1.47, 1.62, 1.81, and 1.94 gea