The d30 is low pinion. The TracLoc was in the D44 rear.
So he has the same front axle as my TJ. He could put a lunchbox locker in the front. I see a few D35 lockers on CL for sale. They are looking for $200-250. You could get them down to maybe $150. I have a lockright D35 locker in my 30 and I love it.