[Stuckinda60s]

I know this is an old thread and not to beat a dead horse, but it might be worth a mention. I saw 2 Blocks that had splits started at the dowel hole, traveled through the block and terminated at the opposite dowel . They both had split pins instead of dowels. At the time I thought that the pins were the cause of the fracture because they weren't an interference fit and only had the spring of the pin for stability, which could be diminished by vibration and allow movement within the hole. They were the 557 block.