Yes and also dont forget the super shaft! Lol
Some of the early 400s had real thick castings in the main web support area. 440 Source has a site where they show pics and measurements of the 383, 400, and 440 block. Very interesting. Some blocks have way more thickness/strength in the main webs. The first 400 blocks had the most. Just type in 440 source, and go to the everything you ever wanted to know about blocks section. Very informative.
There you go, Adam 83. What date was your block cast? Should be on the passenger side, cast into the block above the pan rail. I think the reason they call them super blocks is because of the huge amount of extra casting material around the main bearing journals, as you can see if you look at the pictures. Has to be stronger than the early 383 main bearing supports. If I could have found one, I would have used it for my 451 build. I bought 3-400 engines, and none were the 230 block. They are hard to find.
