318 LA rebuild after losing a valve seat

You can sometimes find single ring sets for purchase. That would explain part of it! Again, use something like oil, not that assembly lube.

BTW.... very important.... in your pix of the reversed rod cap, are the cap bolts snugged down? I ask, as that significant gap showing between ends of the rod bearing halves should not be there. The ends of the bearing halves should butt against each other and slightly crush when you torque the rod fasteners.

Can you put together a rod and cap and bearings oriented in the correct direction and torque the rod fasteners down and look for there to be no gap where the bearing halves meet?