Help identify center diff

[iceminion]

Both the front diff and the Center diff are inside the transmission, there is no real way to verify that he actually has done the mod to it.

Here is what you should do: make sure you know how to reach the seller and put the 4-spider diff to the test! to a 9-grand dump with sticky sticky tires, if the transmission blows up, it will be easy to see that the center diff failed (if it is a 2-spider).

or you could always take the transmission apart, its not that hard.