Fig. 42.4a
If you find a block with three freeze plugs on the side as seen in Fig. 42.4a you can be sure it is a 400-CID, but not all 400-CID blocks had the three freeze plugs some were cast like all the other small-blocks with only two freeze plugs as seen in Fig. 42.4b There is also 400-CID blocks with the third freeze plug boss but no hole.
Fig. 42.4b
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NOTE: Most all 400-CID blocks with three freeze plugs had four bolt mains and 400's with two freeze plugs had only two bolt mains. |