The seat tracks can be tuned up with cleaning and grease, but if you are missing any parts (such as the rollers or ESPECIALLY the nylon bushings) you will have to buy a replacement (new repro or from somebody parting out, preferably the latter - repros are, well, repros - agrarian people from other lands who have never seen a car, much less a Mustang, make them).
My tracks were missing two nylon bushings and had a broken spring or two. I took both tracks apart (the bolts are pressed in and will have to be pressed out to get the rollers out) and cannibalized the passenger bushings to put the driver track in perfect condition, bought a used seat track from my local Mustang guy and combined the parts from that with the parts from my passenger track to make another perfect track.
Assembly/disassembly is tricky, but kinda fun. Make a drawing B4 you start so you know which side goes where and how, etc. (this is not rocket scientry, but it eliminates multiple assembly/disassembly if you make a mistake - and you don't want to press those seat track bolts in an out very many times).
My air ratchet came in handy taking out those seats and putting them back in record time. Undo the back bolts first so the seat doesn't fall back stressing the bolts.
Dan
You are only a doofus until the next round...
http://albums.photopoint.com/j/View?u=1589115&a=12097562&p=45065947.jpg
