You may id your block by different castings that are attached to the block if you can't find a good block ID:
This page shows 1965-'72
This shows 1973-'79
You need to have your head screwed on straight when buying parts from eBay. Many times they don't say what the part number is or what year engine it came from. A 1960 FE engine uses a B8A 7509-A Engine bracket, but a 1961-'64 uses a C2AA 7A572-A. I'm not sure what the newer blocks used.
I call those little rings that hold the heads before assembly, locating bushings. They may have a different name, but new ones come in the gasket sets.