So, it seems that stock block 434 isn't a great idea, unless you spend a significant amount of money to prep it, in which case an aftermarket block is better anyways. So, how about going the 3.875" stroke route? Will a 421 have a better chance of survival? I have two, 2 bolt 400 blocks and a four bolt 400 stock block. Again, planning 13:1, AFR 220 ported head wet sump engine. Just looking for advice/experience regarding what a stock block, with splayed caps, would support. Thanks