The Infamous 53 Block
http://www.cumminsforum.com/articles/articles/53/1/The-Infamous-53-Block/Page1.html
Andy Isaacson
By Andy Isaacson
Published on 04/3/2007
The "53" comes from a casting number on the side of the block, and is used to
identify the problem blocks. Supposedly it affects about 100,000 blocks, but not
only in Dodge Rams. Here is a link to more information on the 53 Block Problem