Larrys Electric - Universal Tuned Port Injection harness Tuned Port Injection stand alone EFI wiring harness . This harness takes care of the headaches involved with installing Tuned port injection on most all SBC engines or swapping a TPI engine into your vehicle, and makes for a much easier installation. Our harnesses are all made with top of the line copper strand wire. TPI Wire Harness | SSW | Standalone GM Wire Harness | LS TPI Wire Harness. 1991 Y-Body design fits the Corvette engine and can also be made to operate the F-Body engines. The computers from this era have someting called VATS (Vehicle Anti-Theft System) this is removed on all Speed Scene Wiring harness through a computer process.