Metal in my 8-3/4 housing. Know what this is??

Does anyone know the pinion nut torque, or if the torque is difference between the 741/2 and 489 housing.
I know that the nut size is larger on the 489 housing.
My service manual says that it is 240 foot pound at the pinion nut for a 489 pinion.

This is a 742 housing.