5.0's are known as the easiest motor to work on and mod. If you ever had a fox you know you could put a crap load of mods, and do a whole bunch of little tricks to make it fast without a tune. 4.6's (2v's) especially the first ones were something even ford technicians didn't like to work on, and if were talking about 4v's, the alldata system says to replace the motor if their is any strange noise out of the motor. I've had them all and you can't beat the reliability of a pushrod motor. You can run a pushrod motor without a rocker arm, or a quart of oil and still make it home.
I like em all don't get me wrong, I'd like to get a 2v again and try the whole cams, p.i swap deal and see what the fuss is about but that npi wasn't close to my old 86 fox.