I personally have cracked 2 different stock 440 blocks, couple hundred runs on each i guess. No girdle or block filler. #2 main saddle cracked up into the cyl wall, same place both blocks. Water in the oil the first clue. Did not throw a rod either time. Took it apart as soon as the milky oil showed up. Eagle 4.15" crank, eagle rods, weisco pistons, B1BS heads, Alum main caps both times. 35 deg timing, 9.00 @ 145 2800lbs, 7200 rpm at the stripe.. Put a world block in no more cracks, 8 years later. On a side note I put 600 runs on aa stock block, crank, main caps, no girdle or block fill. But it had aluminum rods, the rods had .25" side clearance from rubbing on the crank sides. You know what the old saying" it is just a matter of time before a stock block fails at higher power levels. John