HiPo Registry
Frequently Asked Questions
Everything you need to know about the HiPo Registry.
Do I need a complete car to register?
No. The registry is not limited to complete vehicles. You can register an engine, a transmission, an engine-transmission combination, or any other configuration — as long as you have a valid K-Code VIN. Every VIN is valuable to our database, whether it's stamped on a fender apron, an engine block, or a transmission case. Documenting these numbers helps preserve the full production history of the 289 HiPo.
What is a K-Code Mustang?
A K-Code Mustang is a 1965, 1966, or 1967 Ford Mustang equipped with the 289 High Performance engine. The "K" refers to the engine code in position 5 of the 11-character VIN. These engines produced 271 horsepower and used solid lifters, giving them a distinctive character compared to the standard 289.
How do I know if my Mustang is a K-Code?
Check position 5 (the 5th character) of your 11-character VIN stamped on the data plate or door tag. If it's "K", you have a K-Code. Example VIN: 6R09K512345 — the "K" in position 5 (after 09) confirms it's a 289 High Performance.
Is registration free?
Yes. Creating an account and submitting a vehicle to the public registry is completely free. We believe the historical record of these vehicles should be accessible to all enthusiasts and researchers. Optional paid memberships (Silver / Gold) unlock full registry access, vehicle verification, and other benefits — see /membership for details.
What's the difference between Silver and Gold membership?
Both tiers unlock full registry access (full VINs, search, owner contact, verified photos and details) and include a HiPo Registry window sticker for the windshield. Silver includes 1 vehicle verification per year (regardless of monthly or yearly billing); Gold includes 4 per year, the ability to reserve a specific K-number in advance, access to the registry statistics page, plus a personalized window sticker with your K-number, a keychain, a sticker pack, and a printed registry certificate.
What is a vehicle verification?
A verification is an admin review of your vehicle based on photo evidence (VIN stamps, warranty plate, engine and transmission castings) and a short video call to walk through the car. Verified vehicles get an 'Admin Verified' badge, a digital registry certificate with their K-number, and rank higher in the registry. Note: it is a documented plausibility check based on what we can see — not a legal certificate of authenticity or originality. It applies to K-code Mustangs; for Shelby GT350s, authentication is the domain of the Shelby American Automobile Club (SAAC), whose registry holds the factory records — we gladly refer to them.
What happens on the verification video call?
You are at the car and hold each number into the camera while we watch: the fender apron VIN stamp (hood open), the warranty plate (driver's door jamb), the engine VIN stamp and the block casting with its date code, and the transmission casting number, date code and VIN. On a car, the block and transmission numbers are read from underneath — that works without a lift, it is just the fiddliest part, so ramps or jack stands make it much quicker. An engine or gearbox registered on its own needs none of that. Photos alone cannot verify a car; the call is how we know those numbers are on your car and not in someone else's photo. It runs by appointment over FaceTime, WhatsApp or similar, and the exact list for your vehicle is shown before you submit. If the car is in storage or the numbers aren't reachable yet, simply submit later — a verification is only used up when you submit.
What is a K-number?
Every approved vehicle receives a unique sequential K-number (e.g. K-0289) as its certificate identifier. Gold members can reserve a specific available number in advance — useful if a particular number has personal meaning. Once assigned, K-numbers are not reassigned.
How is my privacy protected?
Your full VIN, name, email, and address are never shared publicly. The public listing shows a masked VIN (e.g., 6R09K1***56) that confirms K-Code status while hiding the middle sequence digits. Full VINs are only accessible to members and verified vehicle owners.
How long does approval take?
We review submissions typically within 3–5 business days. We verify that the VIN format is valid for a K-Code Mustang and that the submission appears genuine. You will receive an email notification when your vehicle is approved or if we need additional information.
What photos should I upload?
We recommend uploading: exterior shots (front, rear, both sides, 3/4 angles), interior (dashboard, seats, trunk), engine bay (overview and close-ups of casting numbers and date codes), and any documentation (VIN stamp, warranty plate, owners manual, window sticker, original sales paperwork, title, build sheet). More documentation makes for a stronger record.
My vehicle has a replacement engine. Can I still register?
Yes. We accept vehicles with replacement engines. The registration form has an engine status field where you can select 'Replacement Engine' or 'Unknown'. Many K-Code Mustangs have had engine swaps over the decades — this does not disqualify the vehicle from being a genuine K-Code original.
What are 'numbers matching', 'correct date code' and 'Complete Car'?
For the engine, numbers matching means the block carries your car's VIN stamp — it is the engine the car was built with. Correct date code means the block's casting and date codes fall within the plausible range for your car's assembly date, but it is not provably the original unit. Both are self-reported by the owner. 'Complete Car' on a listing describes the scope of the registration: body, engine and transmission are all registered — the engine either original or a date-code correct replacement. It says nothing about the date codes of other components; that is what the concours world calls 'date-code correct', and it is not something this registry verifies.
What does the 'VIN Checked' badge mean?
A green 'VIN Checked' badge means the owner has submitted photos showing the VIN physically stamped on the vehicle (e.g., on the fender apron or data plate), and a registry administrator has confirmed that the stamped VIN in the photo matches the VIN on file. This adds a layer of confidence that the VIN is tied to a real vehicle — but it is not a guarantee of current ownership, physical condition, or authenticity of the vehicle itself. The registry cannot verify who took the photos or when they were taken.
Still have questions? Contact us and we'll get back to you within 2–3 business days.