94 and 95 Mustangs have a slightly longer bellhousing/input shaft then the fox bodies. the pics of the two different year starters (on advanceautoparts.com) do show the difference. It looks like the older years have the external solenoid(fender mount), where the 94 has the solenoid on the starter. All you really need to do is extend the wires that go to the fender mount solenoid to the 94 starter, and you should be alrite. maybe someone can confirm? I have a 94, and never worked on any older one so....
Good luck
Nick