Golfball size hole in rear differential cover help?

A buddy of mine has a 95 chevy truck 4x4 with 33"x12.5" tires and he just blew something in his rearend. Something put a hole about a golfball size in his differential cover. I took the cover off and there was chunks of a gear but I don't see where from. The ring gear, pinion gear, and spider gears all look good, so I don't know what blew. He messed it up peeling out, ya he's a dumbass, but he's got money so can somone help me out in what is wrong. I can give more information if needed. Any ideas?

Thanks in advance

what kinda rear end is it?

gm 10 bolt, stock probably 3.08 or 3.42 gears

If I was him I would surch for a 14 bolt semi floater or even a full floater. The semi floater is a 9.5" ring gear with bigger axles and brakes, But still incorporates the 6 lug wheels. It was used on the heavy 1/2 tons. If there was chunks of things in there and it isn't gear teath then a bearing probably blew apart. The 10 bolts are not noted for their durability, I had one in a 89 blazer with 35" tires and the bearing race was actually spinning on the carrier and it sheared the carrier off. There was gear teeth and bearings all over inside. I replaced the carrier, ring and pinion all the axle bearings and new axles and with me doing the set-up it was still $1,000.00. Whatever he decides to do make sure you flush the case out real good before assembling it.