Loud grinding noise: won't restart

pulled the motor. I found that the sixth piston rod has split into 3 pieces. It seemed nothing short of a miracle that it didn't crack the block. Also found the other five pistons were black. Turns out the oil pump quit working along time ago. I replaced the rods, oil pump, water pump along with all the seals. it also had a bent valve, so I replaced that. Motor is back in the car and its running good. However, it still has a small oil leak. I find that strange as I just replaced all of the gaskets. Could that be the PCV valve?