91 mustang wiring harness | eBay Find great deals on eBay for 91 mustang wiring harness. Shop with confidence. 91 5.0 - Engine Wiring Harness | Mustang Forums at StangNet Sep 24, 2017Its a 91 5.0 GT manual transmission (mileage unknown as it was an engine swap but I guess about 80k miles). Ill see if I can get a couple pictures posted, but its pretty simple really. the wiring from the computer runs into one end of a S/P connector and then at the other end there is a short (maybe 6-8") pigtail which plugs directly into another S/P shaker and then out to the sensors etc..