it could be a t45 out of an 01 if it was an early production , look on the passenger side of the tranny , if its a T45 , it will say Borg Warner under the gear shifter , if its a tremec 3650 it will say tremec on the side of it little farther forward on the same side of the tranny , I am not sure about the bell housings , I havent seen any major differences on a T45 and Tremec set up , both of the them say tremec on the back of them , so they might be the same , so might not make a difference either way , have to check into that.