New Genuine Mercury OEM Alpha 1 Generation 1 Sterndrive. Replaces pre-Alpha, R and MR drives. Alpha One - The most popular sterndrive in the world. The Alpha 1 Gen 1 Outdrive is available in 1.30 (1.32), 1.47 (1.50), 1.62, 1.81, 1.94 ratios, both standard and opposite rotation. Contact us for help with ratio and rotation. Opposite (left hand) rotation is no longer made, but please contact we have a few left. NOTE: When using the Alpha One Sterndrive Assembly as a replacement on earlier (pre 1983) 4 & 6 cylinder inline models, it will be necessary to replace the standard yoke with a short U���joint yoke. This yoke is not included and must be removed from the old unit.