Before purchasing a new axle for my car, I wanted to pull off my differential cover and make sure I just needed a new axle, and that the diff/posi wasn't damaged as well. Luckily it looks in good shape, but I am puzzled by what I saw. Compared to the pictures of the stock posi unit I saw here http://www.gnttype.org/techarea/pictureguides/rear/stock.html mine is very different. Instead of the standard S-clip to load the clutches, I have a solid I-shaped block. Also, when I rotated the wheels around to see the other side of the carrier, there was this odd-looking mechanism on the other side that spins around very fast when I rotate the tire (like maybe 20-30 revolutions for each revolution of the tire) that I am clueless about. I freely admit my ignorance when it comes to rear-ends, so please, if anyone can PLEASE offer any info I would appreciate it. My main concern is if I DO have a non-stock posi or rear-end, will it affect what axles I need to buy? I was hoping to order the axle this weekend, so the sooner I can figure this out, the better. Thanks again!!! Oh, and here are some pic of both sides of the carrier, so you can see both the I-block, and the funny-looking mechanism. Thanks for the help!