Yes.The 400 blocks are gnerally much stronger than the 440 blocks. Much beefier main webs and reinforcement ribs along the side of the block. 440 mains tend to crack after being pounded on at high h.p levels. 400 might too,but can withstand more pounding before giving up. Good 400 blocks can be used up to the 800 h.p level. In fact there was just such a motor bored out and stroked to 500 cid.With B1 heads it made well over 800 h.p and almost 700 ftlbs tq.
http://www.forabodiesonly.com/mopar/showthread.php?t=124693
Try that with your rod spewing 454 block,lol!!
