Paint and Body GT badges

You cannot tell if it's a GT by the VIN, unless you have access to Ford's production database. (Unless you are Ford Motor Company or Marti Auro Works, you do not. Any "VIN decoder" you find online does not. Your local motor vehicle department does not.) GL or GLX with 5.0L will have the same VIN, i..e they will all start with 1FABP27F or 1FABP28F (27 = convertible, 28 = hatchback, 2nd F = 5.0L).

You cannot tell if it's a GT by the title. See above.

You CAN tell if it's a GT by the codes on the door tag, IF the car was made after 12/82.

You CAN tell if it's a GT by the codes on the buck tag.

ALL 1983 GT's had a blacked out center section on the hood, a "GT" decal on the blacked-out hood, a "GT" decal on each fender above the "5.0" emblem, and a "GT" decal to the right of the "MUSTANG" emblem on the left side of the hatchback liftgate or trunk lid.