I was just curious how many cracked 53 bolcks have been replaced on warranty and out of warranty, how old and how many miles. If on warranty how was it done ie was a new crate motor installed or was old motor parts used in rebuild with new block or what? I recently spoke with someone named Nathan at Cummins hq and he said approx. 1% of the 53s cracked and was given the impression Cummins just used a crate motor each time. Now I've got other imformation Dodge dealers just rebuild on their own. I was also interested to know how owners out of warranty dealt with the issue.