I did an old the thread while back called rod breakers wanted, there's some really good info on just how tough factory rods are. Most rod failures are due to catastrophic failure of other parts that in turn put extreme load on the rods causing a secondary problem broken rod etc. I myself broke a rod cap bolt due to a oil lean deficiency in a 340 the crank continued to beat the rod and bent it about 45 degrees it never did break.
