Ok, I have been searching for an answer but have yet to find one. I know that the block has a tendency to split when its around 500hp, but why is this? Yes, the block was made to be light and less expensive to produce so they took off as much material as they could, which resulted in a weaker block. I was going to do a presentation for my mechanical components class on why the stock block tends to fail around 500hp and why the boss block is better. In the photos comparing the two you can see a big difference between the two, and you can see why the boss block would hold up better. So, I'm looking for an answer as to why does the block split when the hp increases? Is it just because of the added horsepower puts more stress on the block, and the opposing forces split it? I have asked a few people about it and they aren't to sure about it either...