8 3/4 Save or trash???
Every one of those pits is suspect, inside n' out.
Is it worth risking burning up the axles and diff if they open up on a long haul and go unnoticed? i.e. a torsen diff with new gears and custom axles...I wouldn't risk it.
2-series gears on an open diff with salvage yard parts, spot weld it and run. A heavy epoxy overcoating wouldn't hurt but DO NOT coat the inside!
Heat it up and rescrub it. Be surprised what opens up.