ford's modulars are great engines. You wont go wrong even with the older versions, you're just going to give up some power. The 4R100 series tranny will get it done no problem.
But....every modular I've owned, and my buddy has owned, had a habit of busting exhaust manifold bolts, especially passenger side. They've never been a huge issue, but it is definitely an inconvenience to repair. Pay close attention to the condition of the bolts.
Find out if you can when the plugs have been changed, which should have been at 100k max if I recall. I dont remember the model year splits, but certain years had certain issues. Some had issues spitting plugs out of the head, other years had problems with plugs breaking off in the head during replacement. We never had those problems, at all. Again, I dont remember details but supposedly Ford rectified both issues at some point. A good place to go for all things Ford is ford-trucks dot com. Everything you ever wanted to know, plenty you dont, and never ending threads of Gas vs Diesel, but if a Ford engine has a set of pervasive issues you will find out all about it there.
You will easily find out what plug issues there were with whatever model year you are looking at, and the fixes.
If your choice has had them recently changed, I'd arm myself with the knowledge of that years specific issues (if any), and change them again. This way if it was the improper torque issue (spitting plugs) you'll know they've been put in right. If it was the two piece breaking plug problem, you can make sure the updated plugs are installed. Anyway, that website I listed will tell you all you need.
Good luck finding your ride. I loved my V10, just be ready to Feed the Beast. Fuel mileage and Ford V10 don't live in the same world.
