hey bud i did the swap from 4cly to 5.0 in my 93, my doner car was a 91 the only prob i had was the 93 had the fuel pump relay under the hood on the 4cly harness. i wish i new more about the newer ones but i didnt have to touch the dash harness on mine and i bet u wont on your either. i put gt guadge cluster in my v6 and every thing reads fine so i guess the wiring on the 6 and gt are the same. if u want the easy way put a carb on it and a msd ignition. but if u go to
MPS they can help u. good luck the only thing i can tell you is the upper intake will not clear on a sn95 mustang, that why the 94 95 mustang 5.0s had a different upper intake to claer the shock tower, but they my make a adapter for the older intakes.