Mercruiser Alpha One Gen I Outdrives

Mercruiser Alpha One Gen One stern drives were produced from 1984-1990. Improved gear design and bearing arrangements made the Alpha One drive stronger than its "R" Drive predecessor. These Mercruiser Alpha ones come in four different gear ratios: 1.5:1, 1.65:1, 1.84:1 and 1.98:1. The lower housings for all of the Alpha One outdrives use the same lower unit as the gearing is changed in the upper housing.