1million mile isx15 never been touched - what now?

[Road Ranger]

I inframed my cummins isx 500hp 15 5-6 years ago exactly at 800k miles due to blown head gasket and getting coolant in the oil truck just died and never started again lol. Back then cost me around $22.000 with all genuine cummins parts and brand new head. Truck now has 1.25m and still going strong, i was more scared from the old style hpfp with three piston, they say it is a ticking bomb on these engines. That one died at 1 milion miles same thing truck just stopped and did not have engine shavings in the engine, so far the i’m satisfied with the engine.