904 causing knocking noise?
Knowing the statistical cause of death in the slant 6, It's going to poke the #5 rod through the left side of the block. Statistics prove nothing. Could just as easily be the neck on the torque converter that drives the front pump is cracked. A separated piece of that neck cant get away / go anywhere but it can move around a little changing the sound produced. In the few examples I've ran across I could feel it in the floor pan under my feet.