Just in case, you may want someone like Redline who have a jig for doing cut & turns to check your ousing to make sure the kncukle balls or housing tubes arent bent. Those units are strong but your housing shows a lot of signs of having been hammered over the rocks.
If you plan on doing a lift kit, you may even want to have Redline do a cut & turn now while it is all torn down. This way you can have the proper pinion angle & caster on the front with a lift kit.
Randy Rosetta KDØKWX TLCA #19351 69 FJ40 "Meanie" & 1970 Boss 302 Mustang