So I just got a S4 T2 tranny and a GTUs tranny and comparing them, they are the exact same length, everything is located the same, except the t2 has the pan, and they have the same input shaft sizes, I though the splines might be different but I slid the clutch that came off the gtus onto the t2 tranny?

 

GTUs trans is a S5 N/A trans, nothing special about it. N/A Trans do not have a removable bell housing, so why not check that and see if its a real GTUs trans.