Question: Size of 360 oil galley plugs.

I tore down my 360 and am now putting it back together. I am trying to put in the two front oil galley plugs but am having a problem figuring out the right size. (I threw the old ones out without measuring them) I tried 9/16 plugs and they were too small. Then 5/8 and they do not want to go in. I have my local parts store getting me some 19/32 plugs in hopes these will work. My repair manual nor any of the online sites have a specification.

I am hoping someone on this site knows the correct size.

Bob