This is the 128th example of the Chevrolet 427 GM “Anniversary Edition” crate engine, just 427 of these were made, and they used the tooling of the original all-aluminum big-block ZL1 from the late 1960s.
This engine is now being offered for sale out of Garden City, Kansas in original condition with the removed flex plate, a certificate of authenticity, literature, and a rolling engine stand.
This is the 128th example of the Chevrolet 427 “GM “Anniversary Edition” crate engine, just 427 of these were made, and they used the tooling of the original all-aluminum big-block ZL1 from the late 1960s.
History Speedrun: The GM “Anniversary Edition” 427 V8
In 2008 GM Performance Parts lit the American automotive performance world on fire with their release of the the Anniversary Edition 427 – it was a limited-production, all-aluminum big-block crate engine built to commemorate the 50th anniversary of the Chevrolet big block V8.
The engine (sold as part number 19166392) was a modern re-creation of the borderline-mythical ZL1 427, the most powerful engine General Motors ever offered to the public in the 1960s, and perhaps best of all, it was made using the original 1969 ZL1 block tooling.
The ZL1 Tooling Rediscovery
The original ZL1 aluminum blocks made in-period had been cast by the Winters Foundry in Canton, Ohio, they were made from the late 1960s through until 1974. After production ended, the block casting tooling was set aside and eventually mixed in among obsolete equipment at the foundry.
Years later, while clearing out a batch of old tooling, workers at Winters stumbled onto the original ZL1 patterns and molds. They were found to be in remarkably good condition, likely because relatively few blocks had been cast from them over their production life, leaving the tooling well within its useful lifespan.
The discovery was first reported in Vette Magazine’s September 2001 article “Born Again Big-Block.” GM Performance Parts initially used the recovered tooling to produce bare ZL1 blocks for individual sale (as part number 12370850), before developing the full Anniversary Edition crate engine.
As noted in the introduction, this is the 128th of the 427 examples of the GM Anniversary Edition 427 crate engine that were made. Given the heritage of this engine design, these crate engines have been in huge demand, particularly for vintage bowtie muscle car builds.
The GMPP division oversaw the restoration of the tooling and updated some design features of the block casting, including the addition of screw-in galley plugs and strengthening in key structural areas. After the 427th Anniversary Edition engine was produced, the tooling was permanently retired.
The Original ZL1
The story of the ZL1 really begins in 1969, at the height of the muscle car wars. The ZL1 was an all-aluminum 427 cubic inch Mark IV big block developed for Can-Am racing. It had an aluminum block with cast-iron cylinder sleeves, aluminum heads, a solid-lifter camshaft, a 12.0:1 compression ratio, and a single Holley four-barrel carburetor.
GM officially rated it at 430 bhp, but real world output was well above 500. Each engine was hand-assembled in a climate-controlled room at the Tonawanda plant and carefully broken in on a dynamometer.
The ZL1 was never intended for street legal vehicle use. Illinois dealer Fred Gibb, working with Chevrolet Product Promotions Manager Vince Piggins, used the Central Office Production Order (COPO) system (normally reserved for fleet vehicles) to install ZL1 engines in Camaros, circumventing GM’s ban on engines over 400 cubic inches in non-Corvette models.
Only 69 ZL1 Camaros and two ZL1 Corvettes were built. The option added $4,160 to the sticker, back then this was more than the base price of the car itself.
The Anniversary Edition
For the 2008 Anniversary Edition, GM Performance Parts cast new aluminum blocks from the recovered original ZL1 tooling, then paired them with modern internals and a revised top end. Only 427 engines were produced before the tooling was permanently retired.
For the 2008 Anniversary Edition, GM Performance Parts cast new aluminum blocks from the recovered original ZL1 tooling, then paired them with modern internals and a revised top end. Only 427 engines were produced before the tooling was permanently retired.
Key Engine Specifications:
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- Displacement: 427 cubic inches (4.250″ bore × 3.760″ stroke)
- Block: All-aluminum, 4-bolt main caps
- Rotating assembly: Forged steel crankshaft, forged steel connecting rods, forged aluminum pistons
- Compression ratio: 10.1:1
- Cylinder heads: Aluminum oval-port, 110cc chambers, 2.19″/1.88″ valves
- Camshaft: Hydraulic roller (.510″ intake / .540″ exhaust lift)
- Rocker arms: Aluminum roller, 1.7:1 ratio
- Induction: Aluminum oval-port intake with 870 CFM carburetor
- Ignition: HEI distributor
- Rated output: 430 bhp at 5,800 rpm / 444 lb ft at 3,800 rpm
- Recommended fuel: Premium pump gas
The most significant modernization was the hydraulic roller camshaft, replacing the original ZL1’s mechanical flat-tappet cam. This improved street drivability and eliminated the need for regular valve-lash adjustments while maintaining excellent performance. Like the 1969 engine, the rated output is widely considered conservative, with true power believed to exceed 500 bhp.
Each engine shipped in a wooden crate with a numbered certificate of authenticity, engine data plaque with a serial number matching the valve covers, and Anniversary 427 fender emblems. MSRP at launch was $28,625 USD. The engine was designed for pre-1976 street vehicles or any off-road vehicle, though not for marine applications, and was backed by GM’s 24-month/50,000-mile crate engine warranty.
GM also offered the ZZ427 (part number 19166393), a regular-production companion engine sharing the same top end but built on a cast-iron block at a lower price point.
Remaining unused Anniversary Edition engines are rare collectors’ items nowadays, with most of the 427 produced having been installed in COPO Camaro recreations, Corvette resto-mods, and other big block Chevrolet and GM family projects.
The GM Anniversary Edition 427 V8 Shown Here
As noted in the introduction, this is the 128th of the 427 examples of the GM Anniversary Edition 427 crate engine that were made. Given the heritage of this engine design, these crate engines have been in huge demand, particularly for vintage bowtie muscle car builds.
A handful of these engines remain in original, unused condition and we see them come up for sale from time to time and they always generate plenty of interest.
A handful of these engines remain in original, unused condition and we see them come up for sale from time to time and they always generate plenty of interest.
This one is being offered for sale out of Garden City, Kansas on Bring a Trailer with the removed flex plate, a certificate of authenticity, literature, and a rolling engine stand. If you’d like to read more about it or register to bid you can visit the listing here.
Images courtesy of Bring a Trailer
Articles that Ben Branch has written have been covered on CNN, Popular Mechanics, Smithsonian Magazine, Road & Track Magazine, the official Pinterest blog, the official eBay Motors blog, BuzzFeed, Autoweek Magazine, Wired Magazine, Autoblog, Gear Patrol, Jalopnik, The Verge, and many more.
Silodrome was founded by Ben back in 2010, in the years since the site has grown to become a world leader in the alternative and vintage motoring sector, with well over a million monthly readers from around the world and many hundreds of thousands of followers on social media.
