well a rod through the side thats a big fix. yes easier to replace the engine. while a busted casting can be repaired with lock stitching its time consuming and costly. cheaper to find another good running engine.

this is where it gets fun is cat has used the same engine families for decades but made little changes along the way. the only way to tell would be to actually sit em side by side and compare the differences.

The casting cannot be fixed on this motor, it broke it out around the bearing seats for the cam and oil galleries are open too,

ive watch a video of a a engine that had thrown a rod getting repaired. mind you it was a big 6cyl sulzer marine diesel. yes it would be almost impossible to repair this one.