Which engine code is better?

C code is the 2 bbl 289, A code is the standard 4 bbl 289. K code is of course th hi po 289.

If its a C code its not a real GT.


Ford celebrated the first anniversary of the Mustang by introducing the GT Equipment Group on April 17, 1965. The first documented GT was built on 2/20/65. GT stands for the European abbreviation of “Gran Turismo” or “Grand Touring.” The 1965 Mustang GT equipment is a combination of Performance/Appearance package, and could only be ordered on 8-cylinder Mustangs. Pictures of important GT specific items will follow this text.

Required A or K code engine with dual exhaust
5-gauge instrumentation
Dual Exhaust with trumpeted tailpipes exiting through rear valance
Front disk brakes (non-powered) and DISK BRAKE identified on pedal pad
Heavy duty suspension -22/1 steering ratio, 13/16" sway bar, H/D springs and shocks
Fog lights mounted as part of the grill ornament
GT ornamentation badge on front fenders
MUSTANG chrome letters inside of a triple stripe on front fenders
Stripes from front wheel well to rear wheel well
Quarter panel ornaments deleted (coupe and convertible; fastbacks were not offered with quarter panel ornaments)
Mustang emblem and running horse are deleted from front fenders
Rear bumper guards were deleted from the vehicle due to trumpeted exhaust
Rocker panel moldings were not available with the GT package.
Tip #1: Due to the dual exhaust, the rear frame rails have an additional bracket between the inside rails where the rear exhaust hanger bolts go through the frame. The bracket can be felt (not seen) by inserting your finger into the alignment hole (for the trunk floors) in the rear of the frame rail and bending it toward the rear of the vehicle. Also, the rear brake hose is located on the upper portion of the floor pan, about halfway between the frame rail and the driveshaft tunnel, instead of being located near the upper portion of the driveshaft tunnel. Not all cars equipped with dual exhaust were GT’s; however, all GT’s had dual exhaust pipes which exited through the rear valance with the chrome exhaust tips, and the rear valance did not have holes for the rear bumper guards.

Tip #2: The Interior Decor Group (Pony) was introduced at the same time as the GT Equipment Group and could be ordered as an option. This included luxury trim, woodgrain appliqué, ornamentation and deluxe steering wheel, 5-gauge instrument cluster, courtesy door lights, padded visors and chrome trim around the pedals. Not all GT equipped Mustangs had Pony interiors, nor were all Interior Decor Group vehicles GT’s.

Tip #3: Not all cars with the A or K code engines were GT’s. In fact, only about 4% were original factory GT’s.

Tip #4: The quicker ratio steering box that was used on GT’s will have a code of either “HCC AX” or “HCC HW”. The tag is easily visible bolted to the top of the steering gear box. These codes do not guarantee that the car is a factory GT because you could order the quicker ratio apart from the GT in the special handling package. However, a code of HCC AT for the slower gear ratio of 27:1 means that unless the box has been incorrectly changed out, the car could not have been an authentic factory GT.

Tip #5: All 1965 and 1966 GT’s were factory equipped with front disc brakes. The disc brake master cylinder will have a master cylinder cap that clips on, while drum brake master cylinders have a screw-on cap. Disc brake master cylinders are approximately twice the diameter of a drum brake master cylinder.

Tip #6: Only 1965 GT’s came factory equipped with a bright hood lip molding. All 1966 Mustangs were equipped with this molding.

Tip #7: All GT’s were equipped with fog lights. The factory switch to turn them on was located on the underside of the dash, just inside the driver’s side door. When the switch is flipped on, both the fog lights and the rear tail lights light up. Non-factory GT’s with the fog lights added typically are not wired for the tail lights to illuminate when the fog lights are turned on.

Tip #8: The earliest documented GT was built on 2/20/65. If a Mustang was built much before that date, it is unlikely to be a factory GT. Go to the Mustang’s door data tag and look at the build date. If you are unfamiliar with build date codes, check out the date code article on our website. If the door data tag is missing, write down the VIN number that is found on the left front fender apron. Jim Smart & Jim Haskell’s book, In Search of Mustangs provides build date data that will allow you to determine within a few days as to when the Mustang was produced. Certainly close enough to determine if the Mustang could have been a factory GT.

Tip #9: The glove box door on both 1965 and 1966 GT’s is flat and carries the mustache at this upper edges.

Tip #10: 1965 GT’s came with a standard gas cap while all 1966 GT’s came with a gas cap with the letters “GT” on them.

Tip #11: GT’s were not available with bright rocker panel moldings.

Tip #12: GT’s were not available with quarter panel ornaments, which on non-GT’s were located in the sculptured area behind the front doors and on the quarter panel.

Tip #13: On 1965 GT’s the back side of each fog light is secured by a nut. In 1966, lights were secured by a stud screwed into a housing, which is also how the reproduction lights are built today.

GT Equipment Group

1. Special Handling Package
a. Increased rate front and rear springs
b. Larger front and rear shock absorbers
c. Quicker steering ratio of 22:1
d. Larger diameter front stabilizer bar

2. Front disc brakes

3. Fog lamps and grill bar

4. The quicker ratio steering box that was used on GT's will have a code of either HCC-AX or HCC-AW. (HCC-AW is a power steering box.)

5. Five gauge instrument cluster in 1965; standard on all Mustangs in 1966

6. Dual exhaust with chrome trumpets through the rear valance

7. A must option of either the A-code (225 HP Challenger 289 4V) or the K-code (271 HP High Performance 289 4V) engine

8. Standard gas cap in 1965 and GT gas cap in 1966

Ford dealers sold the fog lights, GT badges, deluxe steering wheels, letters and stripe kits as separate dealer installed options and these could be added to any Mustang.

The best way for a hobbyist to identify a “true” factory GT is to find the original Broadcast Sheet or Buck Tag and look for a P10 option (1965/66).

panthers said:

forgive my ignorance, but which engine code best/valuable on a 1965 GT mustang?

A or C?

Thank you.

Click to expand...

For a simple answer to a simple question------ neither one. Both are quite common options.

panthers said:

According to that VIN, that mustang is not an GT, because it has a code C engine?

Also are Code C engines less desirable/powerful/valuable than Code A?

Thank you for your time.

Click to expand...

You are correct. C codes are 200hp 2 bbl motors, with I believe 9:1 compression. A codes are 225hp 4bbl motors with (again if i recall correctly) 9.5:1 compression.

panthers said:

According to that VIN, that mustang is not an GT, because it has a code C engine?

Also are Code C engines less desirable/powerful/valuable than Code A?

Thank you for your time.

Click to expand...

If you are making a concours restoration, then a C code would be worth less. Most people are into restomod type cars, so it isn't that big of a factor. When I bought my 66 fastback, I wasn't concerned with which engine came in it because I was changing everything. It happened to be an A code, but I bought it because it was the best deal.

I have a 1965 Mustang with a VIN of 5R09A150228. Looking at the Smart/Haskells website does not offer me any production numbers close to mine. Can you help with the build date?
Thanks.
I have everything else decoded except for the date.

Try this:
http://averagejoerestoration.com/1965-mustang-vin-and-data-plate-decoder-sheet/