Brad's truck is 15 years old. How about replacing vacuum hoses wholesale? Hose is cheap enough and you would eliminate a few future problems as well.

 

ok guys, this is what i have so far. i had to get a new plenum since i snapped the bolt heads off trying to change the EGR valve. after cleaning the plenum that i got from the junk yard and installing it the rough idle has all but gone away. i also had to order a new throttle body since i snapped the bolt that holds the idle position sensor. just before you say it, i live in new jersey about 2 minutes from the ocean so i believe the salt water has something to do with these bolts corroding like they do. i am going to install the new throttle body on monday after we get through this heat wave. supposed to be 101 today. BTW, i am sure it is a 5.4l. ford only made the 4.2, 4.6 and the 5.4 for this truck in 1997. plus it says so right on the engine and all the lariates came with the 5.4. but i will let you guys know how everything goes after i put the new throttle body on. thanks for all the help, i really do appreciate it.

 

Glad you solved your problem.
Since it's going to be too hot today, why not set up the beach umbrella get a couple of cold ones and see if you can rest up after all that work. Recall watching the ocean looking for ocean going vessels and folks going out deep sea fishing. It was great.
Thanks for keeping us informed on your progress.

 

If it's O.E.M., then is should be a 5.4L. And since i've worked on one just once before, I think (if I'm remembering this correctly), there was a vacuum hose that went from the PCV to the back of the intake (where it's really a bitch to get to) that used a reducer nipple that liked to rot out. This is a quick check.
A few other things to think of. Does this truck crank smoothly (no 'lopes' or speeding up then slowing down) when it cranks? If if doesn't crank easily, then that's a sure sign of internal engine damage; it takes a trained ear, but isn't too hard to discern. A base compression test might be the easiest way to figure this out.
Another is to think that maybe the engine is running OK, but there is another balance problem (like a spun front crank dampner; more likely if this leaks oil all over) or possibly just really weak motor mounts.
Just food for thought.