Well I just finished rebuilding my differential. I did a swap to the 3.73 from the 3.91. Much better driving rpm's and no more clunking and clicking from my old one. I am going to do a full write up on how to rebuild it and it will be posted under the project section of my site. The TSRM calls for a preload of around 17 inch/lbs. and my stock one was 2 inch/lbs! Even the least amount of preload for a used differential is at like 6 or 8 inch/lbs. I have many many pictures to go with my write up. Just thought I would share my accomplishment because the car feels like a new car without all the chattering and carrying on out back. Late.