I have a T4/T3, not a T3/T4, seems to be pretty rare. The turbine housing is a T4. Not sure what wheel it has in it. The Compressor side looks to be a T3 it says .42 on the inside of the outlet. The turbo does say Garrett on the side. I will soon have pictures available. The knoledge of this turbo is said to have 2 passes on it. It is said that the turbo come from a Twin turbo 427 motor. Other turbo not available. It is very clean & no shaft play, it is in very good condition. If anyone is interested let me know, and OFFER a resonable price. Thanks