Holes in main bearing center webs!?

[Steve C]

Can anyone tell me what's up with these holes in the top case half main bearing center webs?
is there something that goes in there? Admittedly it's been a couple months since I tore this thing apart...but as I was washing out the case I found this piece of debris lodged in one of the holes. Not sure what that might be either. The holes go all the way through the center webs.
Thanks for your help gang!

 

[wrenchjohns]

I looked at my crankshaft this morning, the mains have 3 holes, center for alignment and 2 holes into the race on either side of the locator to let oil into the bearing. I don't know what the metal shard is however, the holes look like they may be a very convenient place to prelube the center mains.
john

 

[wrenchjohns]

Or not so convenient, I looked at the case in the laundry tub and the offset of the holes appears different front to back.
john