New oil pump installation

I am rebuilding a 1971 L24 engine and am installing a remanufactured oil pump. The old and the new pumps are identical except the new pump doesn't have the angled oil hole that is on the cylindrical part of the oil pump housing that inserts into the front cover. Instead, the new pump has about a 3/16" hole that goes through the cylindrical housing to the tang area inside the housing where the distributor/oil pump drive shaft meshes with the oil pump(on the old pump, this hole has a metal plug in it). What does the oil hole on the old pump lubricate and will the hole on the side of the new pump accomplish the same thing? I don't want to install this pump if this is critical. Thanks.