is it an lx hatch or coupe? which "303" cam? all ford racing cams were 303. is that all it really has besides an exhaust? kinda pointless....
regardless, if it runs well and everything works, i'd give $4000. maybe $4500 if the paint isn't too bad. take into account, though, that this figure is sight unseen and based solely on what little info you just gave. honestly, more info and some pics would help us make better estimations.
87 GT 308ci
mild h/c/i + suspension + turbo