Do a google search for 5.0 engine swaps (or other similar combinations). A lot of good info on the web, including step-by-step instructions for different applications. I've printed most of the good stuff I found, so I can't just paste in URLs, but I'd recommend getting several different viewpoints. No two people have said exactly the same thing. Are you doing carb or going for an efi setup? Makes a big difference. Which tranny, T5 or AOD?
I'm preparing to swap in my 91 5.0 and T5 into my 67 vert. Not far enough along to tell you all the pitfalls, but it's definitely doable, on the cheap, or however high-end your budget can afford. Do your research, along with whatever good advice you get from here.
I was wondering the same thing, but using an explorer 5.0. Mustang engines are getting harder and harder to find and besides if the explorer already has the gt40 set up with the heads and intake it seems to me a better deal. If I can get the whole harness and computer I think it will be a better runner. The thing I wasn't sure about are the cams that come from the factory but if the cam is more for torque cause of the heavier suv, all the better for a street driven car. Anybody have anything to look out for before starting, thanks for any heads up.