One of the best indicators...
One of the best indicators of originality on a GT or any Mustang for that matter is the door data plate. This door data plate shows signs of wear, but it also has the incorrect rivets as well, making us suspicious. Of course, the door tag needs to match the VIN on the inner fender. A good tip to see if the VIN has been replaced is to look under the fenderwell and see if the area around the VIN has been tampered with.
The venerable and vaulted GT suffers under some of the same angst as other high-performance vehicles. There are probably, per capita, more GTs on the road today than there were when the cars were new. Who can blame the copycats? After all, these cars fetch more money than a standard fastback or hardtop-not only that, but also the GT carries a mystique that draws people.
Even so, when you are out there trying to buy into that mystique, you don't want your purchase to be a Johnny-come-lately or some cobbled-up mess-you want the real thing. Obviously, as fakes go, there are cars that range from poorly done to well done. What is really scary today is that the knowledge on these cars is so great that good fakers can fool even the best experts. All the parts are certainly available to do it, too. You can get all the badging, exhaust hangers, and a correctly riveted door tag from any of the vendors that market Mustang parts.
So with all that said, how can you distinguish a real GT from a fake? You can't, because dealers in 1965 actually "made" GTs. That's right. They did just what today's fakers do: They raided the parts bin and made GTs from standard hardtops, convertibles, and fastbacks. Ouch. This truly adds a certain murky quality to being able to tell a real GT from a fake. Why? Because the Mustang community considers these GTs to be legitimate due to the fact that they were cobbled together at the original-selling dealer.
What Makes a Factory GT
- Exterior
- Foglamps
- Side tape stripe
- GT badging
- GT-lettered gas cap
- Dual trumpet exhaust
- Deleted side chrome
Interior
- Five-dial instrument cluster
Driveline
- 289 4V or 289 4V Hi-Po
- Special handling package
- Front disc brakes
Special K
There are some items that are particular to the Hi-Po, whether it's in the GT or not. Some items are listed in the story, while other obvious items are listed below.
- Special C4 on '66 automatics (quite rare)
- Nine-inch rear axle
- No bumper on the body for the 9-inch pinion snubber (snubber was on the housing)
- Larger, stronger universal joints
GT or Not?
In the final analysis, not only did the convertible turn out to not be a GT, but our '65 was a '66. The best recommendation is that the buyer should beware. Know your GTs, know what they are supposed to have, and try to obtain as much info from the owner as possible. The better armed you are with info, the better you'll be able to discern what the real deal is on the GT.

This convertible supposedly...

This convertible supposedly has the venerable 289 Hi-Po. But does it really? The air cleaner is correct for a '65 Hi-Po GT, but the valve covers are painted-definitely not correct. The GT had chrome covers. This Mustang does have the correct Hi-Po distributor without the vacuum canister-a point in its favor.

Engine tags are nice and this...

Engine tags are nice and this one looks original, but is it really the one for this car? We begin to doubt it simply because the build date of the engine is six months after the car was built. Another thing to look for is a new tag on a car that is in this condition. These should send up a red flag just as readily as this original does.

In photo No. 4, the sway bar...

In photo No. 4, the sway bar seems a bit small when compared to this original GT sway bar. The diameter of the bar should be 1 3/16 inch rather than the standard 1 1/16 inch used on the Mustang.

There are several things to...

There are several things to look for here. The fuel pump is the correct early style, though the likelihood of the original pump still being there is fairly poor. Surprisingly, the car does have the correct Hi-Po balancer (arrow), though the water pump could be considered wrong, as Ford began using cast-iron pumps in June 1965. This is consistent with our engine tag.

Another problem crops up on...

Another problem crops up on our supposed Hi-Po. The alternator should have a large, single pulley on it. This dual pulley is for air conditioning or the extra-cooling package and was not used on the Hi-Po.

Our carburetor seems to be...

Our carburetor seems to be an original Hi-Po unit. What is missing from this picture is the choke cable. In fact, it seems to be missing from the firewall and interior as well. The carb tag (arrow) on any GT should have date codes that are prior to the build date of the car.

Our supposed GT does have...

Our supposed GT does have the correct fan and shroud for cooling the solid lifter engine. It would seem that the car possibly has a K-code engine, even if it was not original to the chassis.

It might be, but we have yet...

It might be, but we have yet to get to the nitty gritty of the car. This badge is no indication of GT status because the 289 Hi-Po was available on the standard Mustang as well.

In this shot, you can see...

In this shot, you can see the rear edge of the correct Hi-Po exhaust manifolds and the correct clutch arm, which uses a hole in the actuator (arrow).

Front disc brakes are another...

Front disc brakes are another staple of the GT. Though, as with so many things, these too can be added to the car with some expense and minimal trouble. Even so, notice whether the car has the brakes and that the pedal pad says Disc Brakes.

The exhaust system on the...

The exhaust system on the GT was the same as any Mustang with duals. This is an area where it used to be more difficult to hide the heritage of the car. Now, the GT exhaust kits are readily available and the kits make it easy to give the car a factory GT look.

Though the valance on the...

Though the valance on the car is kinked, the tips are there. However, the GT gas cap is conspicuous in its absence. Always look for these types of details because they are often your only clues of trouble.

Though at first the interior...

Though at first the interior of the GT looks correct, we noticed that the dashpanel houses a mixed set of glovebox door and instrument clusters. The instrument cluster is correct for a '65 GT, but is not correct for the base interior. This cluster should be camera-case black. The glovebox door is from a '66 model.

Once again, the GT seems to...

Once again, the GT seems to be correct until you start to really notice components such as the foglight switch (arrow). The switch should read FOG. The barrel-type switch is incorrect.

The plot thickens as we realize...

The plot thickens as we realize that the '65 GT is really a '66-and maybe not even a GT at all. The dashpad was changed out and the holes weren't even filled. This might explain the glovebox door.

The grille lights and honeycomb...

The grille lights and honeycomb face are correct for a '65 GT, but with our growing knowledge that this car isn't really what it seems, we are truly skeptical. Don't let flashy appearance blind you to facts.

This is another sign that...

This is another sign that the GT isn't all that it seems to be. The holes were cut for the foglamp wiring harness, but the cutter didn't have the correct size. The actual sizes should be 1 3/16 inch. The holes, however, are not always a sure sign of a true GT. We know of a hardtop that has no hole at all on the passenger side; the wires are simply run through the battery cooling vents.