Engine harness kits are all made from scratch with New Genuine connectors, seals and terminals. Majority of them will come with an ECU programmed with a base file and security removed so the car can be test run before taking to a tuner for a final tune , relays and fuses for all the engine accessories etc... and some times a pedal , auto shifter and BCM - (variation dependent).
Below are some examples of kits we have supplied over the years. If you don't see your combination then don't hesitate to call or email to discuss your particular project.
LSA 6L90e Kit
5L LS1 PCM