i cant tell you the difference in caps in general. but i can tell you that casting numbers from year to year can change allot but know this each cap and girdle is made for the engine its cnc out from. meaning that each cap and girdle is not compatible from one engine to the other unless you get it line honed. it might bolt up or even fit but its not perfect. even if you use arp main stud bolts on a engine you have to get it line honed. it changes the pressure and clearance just from the difference in clamp load. and i dont think that was caused from a bad oil pump. i think a rod broke. i dont see huge bearing wear that would show low oil pressure. i think a rod bolt just simply broke from stress or because it was stretched. but i do only have a limited about of pictures I'm seeing. the head does not look like it took a huge impact from like a bearing spinning and making it possible for the piston to hit the head and also the bearings on the other mains and rods look a little worn but not close to spinning. just my little input hope it helped out thanks