IF that's the one and it's an 86 4-cylinder, then it's not a GT. It's an SE that shared the same body as the 85GT. If it's stock 4-speed and 4-cylinder, then it's an 84 Indy. It's happened before that some people drove a 5-speed as a 4-speed, not knowing it had a 5th gear. I would suspect that the transmission may have been swapped to a 4-speed at some time.
[This message has been edited by fierofool (edited 10-22-2014).]