My only suggestion is if you're into detailing, detail out the car first... Wash, Wax, Clay, then go over it using a DA with a good finishing polish, then look at applying CQuartz, Blakfire or Opti-coat to coat the paint.
Also getting a 3m clear bra on hood, bumper cover, leading edge of fender and fender flares is a good idea.
This will save your paint and clear coat from the nasty conditions you will encounter such as weather, behing stuck behind big-rig trucks going through construction zones etc..
Mechanically, as everyone has stated... under the hood should be fine. Ford's been making 302's for very, very, very long time. And you can't kill the tremec transmissions.
Just check fluids, make sure radiator fluid is flushed and topped... For oil I like synthetic... well, not true synthetic/ Mobil 1.. Check your tires, tire pressure... make sure the spare is in good order. You should be all set!
I did a cross country trip in my 89 Mustang LX 5.0 once. It was fun and some parts were scary too (i.e. going through not so well documented/traveled roads through mountains in Montana)
Enjoy your trip!!!
