360 LA Main Bearing Oil Holes Look Funny?

Hi Everyone! I just picked up a LA 360 block for $400 (hopefully I didn't over pay too much). After getting it home I noticed that there are 2-3 holes drilled into some of the main bearing oil holes. Is this stock or did someone drill into it? If this is not stock how will it effect the blocks strength and oiling system?

Block is a 4179930 – 1975 – 1993, 360 la-series small-block.

IMG_7516.jpg

IMG_7514.jpg

IMG_7515.jpg