'75 A model 8.25 worth upgrading or leave as is?

This is great info, I'm looking to swap a '75 8 1/4" I got for free into my Duster and also need to swap the 2.45:1 open carrier for shorter gears and a Sure Grip. However I'm thinking of using a 3.07:1 ring & pinion from a Jeep Cherokee rear end since they are basically overflowing out of Jeep parts shops and junkyards around here. Anybody know what the options are for limited-slip or locker setups for 8 1/4s? I'm looking for best bang-for-the-buck whether it's LSD or Locker...