Thats news to me..how are the later ones better ? I know the early 400B's have thicker main saddle n web castings ??? 440 source says the later 440RB's are better...I'm just going off the info they have tho.. :elmer:for info
The later ones are more consistent with less core shift. The iron is more evenly dispersed. All the later engines are similar in that aspect, because the casting process kept getting better and better.