Broken Diff

You could have broken a cap also which would have led to broken teeth. Is the housing backbraced? That will help and a steel cap or two won't hurt either. As far as 9"s go, you're probably better off with what you have. The only way a 9" is better is if you throw pretty much all of it away and replace it with aftermarket EVERYTHING. Going to a Dana 60 is actually a reasonable upgrade.