Mercruiser Pre-Alpha Need Help Pleez

[Vortec]

I found a small pin hole in the casting of the lower unit, left side front just above the "hump" for the prop shaft on my 165 Mercruiser pre-alpha drive. (see attached pic) I have this hole on all three of my outdrives and wonder what it is?? I can't imagine it is supposed to be there. Any thoughts anyone?
Thanks!!
Brian

 

[Vortec]

Well after a little research I find that the hole is supposed to be there. It is found on the pre-alpha and alpha units from 74-90.
Whew! I feel a lot more educated now!

 

[Bt Doctur]

Except for the fact the drain hole is on the other side of the case