(https://i.imgur.com/e7wo7T5.jpeg)
Which area is this? It may not really be a problem.....
This is the area where the driver's side differential bearing is located; the side that gets shimmed and side covers installed. The stud in the picture goes to one of the holes in the top of the differential cover, driver's side.
I probably would go ahead and use it, as long as the bores don't look damaged, and it's the only one thats cracked.