[papajam]

Great shot, jpv. (hope you don't mind I borrowed it)

yng,
One arrow points to the triangular shaped ribbing I mentioned. Non-LSDs do not have this triangle. In addition, the second arrow points to the three center cooling fins on the oilpan. These three fins on an LSD rear are longer than the other fins; on non-LSD, the cooling fins are the same length.