That be a Ford 302 mated to a pre-alpha #1 drive. You will likely have either a Holley 2300 carb or a Rochester 2GC. Most likely the Holley in that age. Mercruiser offered that engine combo until '77.
You could call it a 5.0 liter (Ford did later), but in the realm of Mercruiser, a 5.0 usually means a Chevy 305.
