The Shelby Cobra Program

The master reference page for the Shelby Cobra program — the cars, the people, the chassis-number conventions, the production history, and the replica industry that the original program inspired.

This is a working seed. Some sections are populated from verified site content; others are marked for Phase 1 buildout. Every fact must trace to a cited source before publication.

The Shelby Cobra is the 1960s American sports car that paired Ford small-block V8 engines with the British AC Ace chassis. Approximately 1,000 originals were built between 1962 and 1967, of which only 160 are the "427" big-block version. The program ended in 1967, but Shelby American continues to produce continuation cars under the CSX6000, CSX7000, and CSX8000 designations, and a robust licensed and unlicensed replica industry has built tens of thousands of tributes in the decades since.

AC Cars: the pre-Cobra heritage

AC Cars predates the Shelby Cobra by six decades. The Cobra is the most famous chapter in the company’s history, but it sits on top of an older British coachbuilding tradition that produced the Ace — the platform Shelby would later use.

• John Weller, the designer who founded the company that became AC Cars, was born on November 28, 1877.
• 1900 — Weller Brothers Engineering formed in West Norwood, London.
• 1902 — partnered with John Portwine to form Weller Bros, Ltd.
• 1904 — renamed Autocar and Accessories, Ltd.
• 1907 — renamed Autocarriers, Ltd. The abbreviation "AC" was adopted as the company’s logo and became the brand name.
• 1911 — moved operations to the Ferry Works facility in Thames Ditton, Surrey, England, the home of AC Cars production for approximately 70 years.
• 1921-22 — Selwyn Edge became Governing Director, then gained full control in 1922.

By the late 1950s, AC was producing the Ace and Ace-Bristol, lightweight sports cars that found racing success in Europe and the United States. The Ace-Bristol won at Le Mans, Sebring, and in SCCA national championships between 1957 and 1961. The Ace chassis would become the foundation of the Shelby Cobra.

Key development figures for the AC Ace:

• John Tojeiro
• Vin Davison
• Eric Gray

Phase 1 buildout: Carroll Shelby’s background, the 1961-62 partnership formation with AC Cars, the Ford engine supply deal, and the move to Shelby American’s Venice, California facility are still to be researched and added from cited sources.

Original production (1962–1967)

The original Shelby Cobra program ran from 1962 through 1967. Approximately 1,000 cars were built across all variants.

| Phase | Year | Defining change |
|—|—|—|
| 260 prototype | January 1962 | First Cobra built; 260 cubic inch Ford small-block V8 |
| 289 standardized | 1963 | 289 cubic inch V8 became the production engine |
| MkII | mid-1960s | Rack-and-pinion steering introduced |
| MkIII | 1965 | Major redesign; chassis used for the 427 big-block program |

Of the roughly 1,000 originals, only 160 are the genuine "427" version (the 427 cubic inch big-block cars). The 427 is the headline car of the program — the most valuable, most aggressive, and rarest of the originals.

Phase 1 buildout: total production numbers per chassis prefix, Le Mans entries and results, the FIA championship history, the Daytona Coupe program, and the specific dates marking the end of production are still to be researched and added.

Chassis number prefix conventions

The Cobra world is organized around chassis number prefixes. Each prefix encodes era, engine size, and origin. This is the most important reference point for any build article on the site.

Original Shelby American chassis prefixes

• CSX — leaded-frame 260/289 cars (CSX2000–CSX2602 range). The earliest production Cobras.
• CSX2 — later 289 cars with rack-and-pinion steering (MkII era).
• CSX3 — 427 / 428 big-block cars (CSX3001–CSX3360 range). The "427 Cobras."
• COB / COX — AC Cars’ own chassis numbering used for AC-built Cobras and Aces destined for markets other than the US.

Shelby American continuation series

Shelby American restarted Cobra production in the 1990s with new chassis prefixes. These are factory-built continuation cars, not replicas — Shelby American is the only entity authorized to use original-format Shelby chassis numbering on new cars.

• CSX4000 — 427 Cobras, continuation series. Production started in 1997.
• CSX6000 — current production. The 427 S/C Cobra. Sold as rolling chassis without engine and transmission; dealers install running gear for customers.
• CSX7000 — current production. The 289 FIA Cobra.
• CSX8000 — current production. The 289 Street Cobra.

Replica manufacturer prefixes

Each major replica manufacturer uses its own chassis number prefix.

• BDR — Backdraft Racing
• SP / SP0 — Superformance (the only manufacturer licensed by Carroll Shelby Licensing, Inc.)
• KMP — Kirkham Motorsports
• FFR — Factory Five Racing
• ERA — ERA Replica Automobiles

For full per-manufacturer detail, see the corresponding pages under knowledge/manufacturers/.

The replica and continuation taxonomy

The Cobra world divides into five categories. The site uses these definitions consistently — they’re the basis for how every build article is categorized.

• Originals — the ~1,000 cars built between 1962 and 1967 by Shelby American and AC Cars. The genuine pre-1968 chassis. Provenance is everything; SAAC registry data is authoritative.
• Continuations (recreations) — factory-built new cars from Shelby American using original-format chassis numbering (CSX4000 onward). Sold as rolling chassis without drivetrain to skirt US new-car regulations; dealers install engine and transmission. The closest thing to a "new" original Cobra you can buy.
• Replicas — high-quality reproductions built by licensed or unlicensed manufacturers, typically turnkey-minus-drivetrain. Backdraft, Superformance, Kirkham, ERA, and others.
• Kits — unassembled components shipped to a customer who builds the car themselves. Factory Five Racing is the volume leader. Build quality is the assembler’s responsibility, not the kit manufacturer’s.
• Component cars — partially assembled vehicles (rolling chassis) missing engine, transmission, and final paint. Sold this way for the same regulatory reason as continuations.

A Cobra Authority build article will identify which category applies in the first paragraph, by category and by chassis number.

The replica era — overview

A robust industry of Cobra replicas, continuations, and tributes has grown up around the original program. The manufacturer overview pages under knowledge/manufacturers/ document each in detail. A brief orientation:

• Shelby American restarted production in 1997 with the CSX4000-series 427 Cobras and continues today with CSX6000/7000/8000 continuation lines. The only producer authorized to use original-format Shelby chassis numbering on new cars.
• Superformance founded 1996 by Hi-Tech Automotive, Ltd. The only manufacturer licensed by Carroll Shelby Licensing, Inc. to build reproductions. Models: MKII 289 Slab Side, MKII 289 FIA, MKIII 427 S/C, MKIII 427 Roadster, MKIII-CS 427.
• Kirkham Motorsports founded 1994 by David Kirkham. Polish manufacturing of aluminum bodies and chassis in a Mielec facility; US assembly through Shelby American dealers in Las Vegas. Models: 427 KMS/SC, 427 Street, 289 Street, 289 FIA. The premium replica option both in price and in authenticity of construction.
• Backdraft Racing founded January 2001 by Tony Marten and Reg Dodd. 53,000 sq.ft. facility in Boynton Beach, Florida, opened 2012. Models: RT4 Classic Edition, RT4B Black Edition. Turn-key minus drivetrain; buyer specs the engine and transmission.
• Factory Five Racing — Massachusetts-based. Volume leader in kit Cobras with tens of thousands of builds. The buyer assembles the car from a kit and a sourced drivetrain.
• ERA Replica Automobiles founded 1981. Models: 289 Slabside, 289 FIA, 427SC.
• Shell Valley, Unique Motorcars, Hurricane Motorsports — additional manufacturers covered in their own pages once those are written.

Cross-links

• All manufacturer overviews: knowledge/manufacturers/*.md
• All chassis-family pages: knowledge/chassis-families/*.md
• Style and voice rules: HANDOFF.md

Sources for this draft

• Cobra Authority — The History of AC Cars and the Birth of the Shelby Cobra: https://cobra-authority.com/the-history-of-ac-cars-and-the-birth-of-the-shelby-cobra/
• Cobra Authority — Shelby Cobra: A Buyer’s Guide to Originals, Kits, Replicas, Tributes, and Continuation Cars: https://cobra-authority.com/shelby-cobra-a-buyers-guide-to-originals-kits-replicas-tributes-continuation-cars/
• Cobra Authority — Kirkham Motorsports: https://cobra-authority.com/kirkham-motorsports/

Additional sources to be added during Phase 1 buildout: SAAC registry, Carroll Shelby biographical materials, Le Mans race archives, and each manufacturer’s own published material.

Last reviewed: May 16, 2026