Small Block chevy 327 (1964) as shown in picture there are three holes for the water pump on the left and two on the right. The top two bolts on left are for securing the pump to the block. The bottom hole on the left feeds directly to the oil drain hole on the cylinder head. There is a matching hole on the waterpump side ! Now my question is, Why does the waterpump need engine oil. There is no oil pressure to this hole it is gravity fed. I have extenuated my resources people maybe one of you car nuts can figure this one out. Thanks Homer