I guess the issue really boils down to whether I need a 14mm key or 14mm socket because of the lack of room. Since Sears was the only place I found it (part of a kit), $40 is a bit to spend only to find out it won't do the job. I have the fluid and a pump because I expected I would be changing the fluid.
The other is that I'm generally paranoid after I do any work and like to know what to look, and listen for to see if anything is wrong. I thought maybe some whining or something if the diff was starved.
I'm going to be back under the car this weekend because I have to change the oil filter housing casket (the one at the block).