If you just want 5-lug, Ranger rotors will fit right on your 86. They are the same size but 5-lug. You would need change your spindles to V8 ones in order to use the lincoln rotors or go with all 94-95 stuff.
But to answer your basic question, the 79-86 and 87+ 4cyl rotors are 10" instead of 11" like on the 87-93 V8 cars.