I will post a few just for referance. I am taking this engine completely apart so as I dont get any shavings in places that I dont want. I used the head as a template to drill/mark the locations of the oil drain back holes on the block surface. The holes that my philips screw driver is pointing at were not there at all prior to me drilling. I sonic tested that area for my own knowledge and there is no issues of hitting water especially since I will drill some at an angle towards the valley and grind others that simply need minimal work to allow oil drain back.