340 help

I have a 67 block with the plug in it. but mine is cracked around the plug which caused the oil and water to mix. I think I'm going to have it welded.
We picked up the block from the machine shop they said it was a good block. I have never dealt with the early 340 so I was stumped when I seen what looked like plugs in the block but with the good help from all on here they help me out. Thanks again KB9GIB southern Illinois.