2013 ISX 15 rapid sudden coolant consumption

[Nerv]

Quick update, dropped pan and found decent sized metal pieces in pan(silver colour magnetic),opened filter (no metal shaving) immediately saw coolant dripping down #2 liner, pressured system overnight to be certain and had a decent amount of coolant leaking. Pulled head off, all gear train is in great shape. fire ring on number #2 was just slightly cracked, measured liner protrusion with 100ft lbs on liner install tool, 0.004 on passanger side #2, 0.010 on driver side. Removed pistons, bearings and liners look great for 900,000miles on them, still cant find any damage(pic posted if anyone has a clue where metal came from) glad im doing this now as I definitely had that #2 liner drop). Im waiting for my liner removal tool which comes In tomorrow hopefully, after that Ill pull one of the mains to verify part #, and will do so on each one. My question now is i searched esn on cummins and im getting rebuild kit #5693737, this lists the rod bearings as #4089405 rod bearing set and #2882087 con rod bearing kit. My rod bearing part numbers are #3686436 and #3686435. What am I missing here between these numbers, I can find that the #2882087 interchanges with mine but what is the #4089405 rod bearing set. The piston number is also different then the pistons i have removed, are these just the part numbers of the entire kit? Just want to be certain all parts are proper. Im following all recommendations and taking my time to guarantee another million miles+, no point in investing this money to have to dish it out again if it doesnt drive me in the hole at that point. Thanks for all the insite, glad to have this information, not a mechanic but when I talk to most of them have no clue about any of this shi#t. Makes you wonder how much damage their doing..