I have a 2000 f150 7700pck with a 373 open (axle code 26)rear diff. I was just wondering if it's possible to change this diff to a limited slip 373 or do I have to replace the whole assembly.

 

You can add an aftermarket limited slip without a gear change. 4 wheel parts installed mine. $700+ installed. I had the Auburn unit installed. The unit did exactly what I had hoped for. I went turkey hunting in the middle of nowhere the day it was installed and the rain had been very heavy. I was also towing a small camper. As soon as I got to the mud the LS kicked in and instead of fishtailing in every muddy spot, the truck charged through all of them. It even climbed a hill that was mud pulling the camper. It is no doubt the most practical modification I've made. I worried about getting stuck on many occasion. Those days are over. It made a huge difference.

Hunt4Fun