My 340 bare block

Some pictures of the 340 block that I received with my 69 Dart and parts package. What I'm going to show you here are some holes drilled in the lifter valley .
I thought that a friend of mine knew something about the past of this block , wrong. I was hoping he would be able to tell me where the machine work has been done and what these holes were drilled for.
A description first.
At the front of the block right hand side passenger side oil galley there's a hole drilled directly below the large hole going into the cam cover at the front wall. I don't exactly what that hole is for in the wall certainly not a drain into the timing chain area. It's about 9/16 in diameter maybe 5/8. The drilled hole is about an eighth of an inch diameter. And the same location on the left side driver side there is a center drill mark. As if they maybe were planning to drill a hole there in the left-hand oil galley.
Then looking to the rear of the block there is another hole approximately 1/8 of an inch. That hole is located in the passageway leading to the pressure send port.
I'll post a cpl. pics maybe some of you guys 'n gals might know what was up here and the thinking and reasoning behind it. I've read the Guitar Jones Oil mod thread I don't believe any thing like this was in there. I can always plug them. not a problem , and go with something I know a little more about like some of the guitar Jones mods.