I wouldn't run steel rods if you gave them to me. Steel rods take all the vibration from detonation and put it into the crank. The crank is bouncing and shaking in a cast iron block. It doesn't take a rocket scientist to figure out that cast iron will crack after being beat on that much. Look at a steel rod engines main caps then look at the one running alluminum rods. Alluminum rods for me I have ran them for 15 years without ever having a rod failure. Some had over 1,000 miles on the odometer of pure drag racing.

Leon