The best thing for that truck is a duall exaust and leave the rest alone.If it has the factory exaust on it still.I have a 89 and from 2 foot away you cant even hear the biggest engine ford made running,The muffler /exaust is very restrictive.Then if you want to get real tricky you can cut the air horns out of the intake hoses.If that is still stock the engine is breathing out of 2 quater size holes .You will loose a little low end from these mods,but it will not stop pulling at 3800 rpm after that.There is a plastic piece in the middle of the intake hoses ,look at both sides of that to see the air horns.
Ohh and to answer your question the fuel injected motors are straight up timing starting 86-87. It started in 71-72 and went till the fuel injection.