Problem with Cats (I love them) is that they don’t have a reman program. So you pay a lot more per HP unless you know a great Cat shop that can find a pair of good blocks and rebuild them. AND stand behind their work. When I went thru this decision process for my 53, I talked to the owner of a Cat shop I ve been using for over 10 years for the car powered boats I run and he told me there was no way I could get the bang for the buck of the Cummins reman program. It s a good block with all new parts.