This is a GM Anniversary Edition Chevrolet 427 crate engine that remains in its factory crate, having never been used. This is engine #166 of the #427 that were made, and it’s capable of 430 bhp and 444 lb ft of torque.
These engines have a fascinating story that dates back to the late 1960s when the first ZL1 V8s were made. The tooling was then rediscovered decades later, and a new run of engines were commissioned, you can read the full story below.
This is a GM Anniversary Edition Chevrolet 427 crate engine that remains in its factory crate, having never been used. This is engine #166 of the #427 that were made, and it’s capable of 430 bhp and 444 lb ft of torque.
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.
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 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.
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.
It comes with a Holley carburetor that was supplied when the engine was initially purchased, a certificate of authenticity, and the shipping crate. The front of the cylinder heads are both machined smooth and inscribed with the “GM Performance Parts” logo, and the engine block is stamped with the engine’s sequential number of #166
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.
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
The engine you see here is #166 of the #427 units that were made, as noted in the introduction, and it’s remained on its factory shipping pallet with its crate since new in original, unused condition.
The engine you see here is #166 of the #427 units that were made, as noted in the introduction, and it’s remained on its factory shipping pallet with its crate since new in original, unused condition.
It comes with a Holley carburetor that was supplied when the engine was initially purchased, a certificate of authenticity, and the shipping crate. The front of the cylinder heads are both machined smooth and inscribed with the “GM Performance Parts” logo, and the engine block is stamped with the engine’s sequential number of #166
The engine is now being offered for sale out of Monroe Township, New Jersey on Bring a Trailer and you can visit the listing here if you’d like to read more about it or place a bid.
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.
