Cummings long-block purchase.

Is the coolest issue something that can be remedied when I have the engine out?

Any idea what causes this failure and how to avoid it in the future?

I'm getting ready to pull the engine, when I'm doing that I will investigate the failure point and possible repair options.

I'm not 100 percent sold on a new long block but with how hard it is to find a good machine shop, how expensive machine work is, how long machine work seems to take, ect, I figure it's probably not much more to just replace everything vs have mine worked on.
It’s basically a pressure imbalance due to the design of the new head for the Common rail, there’s a coolant kit that you can buy for around 350 bucks that will solve the issue.