The AC Cobra, an automotive legend born in 1962 from the partnership between AC Cars and Carroll Shelby, remains today one of the most widely replicated cars in the world. Its lightweight chassis, timeless silhouette, and raw character have inspired generations of enthusiasts to build their own version—often more reliable, more powerful, or better suited to modern road use.
The choice of engine is the central element of a replica, as it determines not only the available power, but also the balance, road behavior, sound signature, reliability, and overall authenticity of the project.
There are four main families of powerplants: Ford small blocks, Ford big blocks, Chevrolet engines, and modern alternatives (Ford Coyote, Godzilla, custom-built engines, etc.).
427 Side oiler
Ford 289 (4.7 L)
The most iconic engine, as it powered the early “FIA” Cobra 289 models.
Typical power in replicas: 280 to 350 hp
Advantages: lightweight, crisp and high-pitched sound, well-balanced handling
Ideal for: purists, reliability, and spirited road driving
Ford 302 (5.0 L)
The most widespread small block during the 1980s–1990s.
Power: 260 to 400 hp, depending on build
Advantages: parts available everywhere, very reasonable cost, strong reliability
Highly popular in British replicas (DAX, Pilgrim, AK, etc.)
Ford 351 Windsor (5.8 L)
The best power-to-weight compromise.
Power: 350 to 500+ hp depending on configuration
Advantages: strong torque, robust architecture, still relatively lightweight
Excellent for builders wanting a powerful Cobra without going to extremes
Engine options for Shelby Cobra
This is the iconic configuration of the legendary “427” Cobras, the most famous of all.
Ford FE 427 (7.0 L) — the ultimate Holy Grail
The engine of the original Cobra 427 S/C.
Power in replicas: 400 to 600 hp, and often much more
Advantages: ultimate authenticity, massive torque, unmistakable sound
Drawbacks: very high cost, significant weight, substantial heat output
Other FE engines: 390, 410, 428
Often used in replicas to keep costs under control.
Typical power: 350 to 450 hp
Advantages: same FE block as the 427, identical appearance, much lower price
Perfect for: a faithful big-block Cobra without an excessive budget
Ford 460 / 514 (7.5 to 8.4 L)
Modern big blocks from the 385 series.
Power: 500 to 700 hp
Advantages: monstrous output, parts readily available
Drawbacks: very heavy, high heat generation, require a properly reinforced chassis
Although Shelby never wanted Chevrolet engines, many replicas use them for their excellent performance-to-price ratio.
Chevrolet 350 Small Block (5.7 L)
The most popular American V8 of all time.
Power: 250 to 450 hp
Advantages: extremely reliable, very inexpensive parts, huge range of upgrade options
Ideal for: tight budgets or reliability-focused builds
Chevrolet 383 Stroker
An evolution of the 350 with increased torque.
Power: 400–500 hp
Classic “muscle car” sound, highly appreciated
LS Series (LS1, LS2, LS3, LS7)
GM’s modern and lightweight generation of V8 engines.
Power: 350 to 650 hp depending on version
Advantages: reduced weight, modern engine management, reliability, reasonable fuel consumption
Drawback: less “vintage” in both appearance and sound
Chevrolet Big Block 454 / 502
For a truly monstrous Cobra.
Power: 450 to 750 hp
Advantages: titanic torque, imposing visual presence
Drawbacks: significant front-end weight, requires upgraded brakes and suspension
Lake of Geneva, Switzerland
Ford Coyote 5.0 (Gen 1 to Gen 4)
The modern V8 found in Mustangs.
Power: 420 to 480 hp
Advantages: very reliable, modern design, DOHC (4 camshafts) — smoother behavior and strong high-rpm performance
Drawbacks: very wide engine, complex installation in some chassis
Ford Godzilla 7.3 L
Ford’s new V8 with a single camshaft and massive torque.
Power: 430 to 550+ hp
Advantages: enormous torque, extremely robust, “old school” look despite its modern design
Now starting to appear in high-end replicas
Roush Engines (Ford)
Turnkey, factory-built Ford performance engines, very popular.
427SR, 427R, 402R…
Power: 500 to 600 hp
Advantages: reliability, warranty, outstanding appearance
Custom engines / specialist builders
Blueprint Engines
Keith Craft
Shelby Engines (Las Vegas)
Danbury Competition Engines
These builders offer custom-built engines, often aimed at high-end Cobra replicas.
For absolute authenticity:
Ford FE 427
Ford 289
This is the most historically faithful configuration.
For an excellent performance/reliability balance:
Ford 351 Windsor
Chevrolet 383 Stroker
LS3
For an extreme, no-compromise Cobra:
Ford 460 / 514
Chevrolet 502 Big Block
LS7
For modern / GT-style driving:
Ford Coyote
Ford Godzilla
South of France