If it's a inferno sport it'll only have two spider gears. Get the kanai or 777 diff gears, they have four spider gears and you'll be pretty unlucky to break them.

If you stripped the pinion gear it sounds like you need to shim the diff. Thin washers are put over the things the dog bones go into (forget the name) to push the diff to the side. Not enough and it strips, too many and it strips, just enough and it'll last for ages.