This harness is designed to plug directly into the Chevrolet performance bulk head connector. It will let you use a 6L80E or 6L90E with the Chevrolet Performance LS3, LSA, LSX crate engines. It will require a special program in the transmission controller to work with the Chevrolet Performance LS engine controller (which we have). This harness is setup to connect with our SFT5000 Floor shifter. If you are using our paddle shifter, use harness TCM-4410.