Like the topic says, how do I tell if it's a ITR tranny, CTR of just a GSR with LSD? I'm sure it has a LSD because I can see through where the axles go. There is no writing anywhere on the tranny. Any help will be appreciated, thanks.

Reason why I ask is because I just bought a tranny from Salbeja, and he told me it was a 2000 USDM tranny, which I'm pretty sure it's not since it doesn't even have a serial number on it.