Re: alpha 1 HP
An Alpha 1 is a specific model of sterndrive, made by Mercury marine, also referred to as a "Mercruiser Alpha I". Note that an alpha I comes in several generations, gen I (older) would not be compatible parts wise with gen 2/3. The Alpha drives can handle generally up to 300 horsepower of motor output. After 300 you need to go to a Bravo drive or another brand like Volvo Penta with a higher hp rating.
That motor I don't know specifically, but just based on the size and type I'm guessing about 230-240 horsepower with a 2 barrel.
Erik
