327 Question???

Ok, I just picked up 2 engines yesterday for 50$. Guy said they were both 350's but he was wrong. One is a 350 four bolt and the other a two bolt 327. Now on the front of the engine under the timing cover there are two plugs, what are these for? I have never seen these before in a small block. The plugs are very large and are located on both sides of the top of the timing chain just below the three little soft plugs for the oil galley. On other blocks it's cast in metal not these huge plugs. I have a 283 block from '64 and it doesn't even have them. The engine is from '67 and is a small journal.