[dataway]

For whatever you need, check McMaster-Carr they will have most everything. Heli-coils are also available without the tab.

Others may disagree but I don't think a few aluminum shavings in the pan would be an issue. They would almost certainly remain in the pan and the pump screen should stop anything large enough to be a problem in the pump, then the filter would catch the rest. (although ... check balls get stuck pretty easy).

As Grandam suggested, there are ways to catch the chips on the back side. Heck you could probably bend up a little spoon out of aluminum foil, put some grease in it and hold it behind the hole.

I think the drilling would be the biggest issue, might need smallish right angle drill, or attachment for a conventional drill to get in there ... and I bet it still might be too close to the block to get the drill straight. Maybe a right angle drill with a long bit to clear the block might work.

I'd check if you have room before you decide on anything. Working a 3/8 tap in there with an extension, without drilling may be the only way. There may be some right angle air drills small enough to do the job.