The harness will work, but the computer may or may not. Some of the 5.0 vics were non-HO. The mustang is HO. The way to tell if your engine is an HO engine is by the firing order (HO being 1-3-7-2-6-5-4-8, non-HO being 1-5-4-2-6-3-7-8). You need a computer to match weather it is HO or non-HO. Also, if you are going to be running a mass-air sensor, the engine has to be HO with either a A9L or A9P computer. Check out
www.fordfuelinjection.com for more info.