Thread: 2009 GM 427 ZL-1 big block

GM Performance Parts (GMPP) announced production plans for a new Anniversary 427 limited-edition crate engine and a regular-production ZZ427 crate engine. The Anniversary 427 is a modern re-creation of the mythical, all-aluminum ZL-1 427 engine. It is underrated at 430 horsepower and 450 lb.-ft. of torque – like the production engine was in 1969. Only 427 of the special engines will be built.

The new ZZ427 crate engine features most the Anniversary 427's high-performance design features and components, but is built with a more economical cast iron cylinder block – but still producing approximately 430 horses and 450 lb-ft. of twisting power. The ZZ427 enters the GM Performance Parts crate engine lineup as a regular-production power plant.

"Simply mentioning the term 'ZL-1' stirs the emotions of Chevy performance enthusiasts," said Lisa Reffett, marketing manager, GM Performance Parts. "By using the tooling that built the original engines, we're able to revive the spirit of that legend and re-introduce it to not only enthusiasts who missed their opportunity to own one 40 years ago, but to a new generation of Chevy high-performance fans."

The 427 copies of the Anniversary 427 go on sale in the first quarter of 2008 through GM dealers and authorized GM Performance Parts retailers. Each engine also comes with a complementing Anniversary Edition package that includes a certificate of authenticity, an engine plate with specifications and a matching number owner's kit to add to its exclusivity.

"The Anniversary 427 is a special engine, and the lucky customers who buy one will know they got something unique," said Reffett. "Cars are collectable and we're sure the Anniversary 427 will be, too."

ZL-1 tooling

Production of the Anniversary 427 was inspired by the discovery of the signature aluminum block's tooling several years ago. It was discarded after production of the original ZL-1 engine halted in the early 1970s.

GM Performance Parts oversaw the refurbishment of the tooling and updated some design features of the cylinder block, such as the addition of screw-in galley plugs. The block casting also was strengthened in key areas. The result is a modern interpretation of the legendary engine that is infused with all of the high-performance attributes of the original.

The all-new Anniversary 427 has a classic, single four-barrel carburetor induction system that is similar to the four-barrel setup of the original ZL-1 engine. (GMPP offered a port-fuel-injected "Ram Jet ZL-1" crate engine a few years ago, with a block based on the refurbished aluminum ZL-1.)

Anniversary 427 and ZZ427 engine details

The limited-production Anniversary 427 – GM part number 19166392 – and regular-production ZZ427 – 19166393 – share similar design traits that combine with carefully selected components from the GM Performance Parts catalog to produce approximately 430 horsepower and 450 lb.-ft. of torque; it's just that the Anniversary 427 uses the special, re-tooled aluminum cylinder block casting.

These new 427 engines accept all of GMPP's front-end accessory drive systems and lightweight starters. Customers will need to supply fuel system and exhaust system components as needed for their application.

ZL-1 history

The 427-cubic-inch ZL-1 engine was born in the late 1960s as a lightweight weapon for use in road racing and the first few were handed out to racing teams supported by Chevrolet. The aluminum block offered an approximately 100-pound weight savings over the conventional iron big-block casting.

Dealers got wind of the engine, which was said to make more than 500 horsepower when properly tuned, and a few production cars were ordered under Chevy's "COPO" system – a special-order system that was used mostly for fleet vehicles, such as utility trucks or taxi cabs. COPO stood for Central Office Production Order, and the dealers exploited the rules of the system to custom-build the ultimate muscle cars.

In all, 69 1969 Camaros and a pair of 1969 Corvettes were built with the ZL-1 engine as standard equipment. Most of the vehicles were ordered with few options, as they were intended to be sold to drag racers. Nearly 40 years later, they are the most prized and valuable Chevy models of the muscle car heyday.

While production cars with the ZL-1 engine were available for only a year, Chevrolet continued to manufacture and sell ZL-1 engines and parts over the parts counter to racers through the early 1970s. So, while the ZL-1 engine program ended, its legacy lingered for decades.

GM Performance Parts crate engines undergo a 50-hour, full-throttle engine dynamometer validation, requiring the engines perform from peak horsepower to peak torque. GMPP also installs crate engines in its own engineering vehicles for ongoing testing and continuous improvement. This commitment to quality and durability allows General Motors to back GM Performance Parts crate engines with a 24-month / 50,000-mile warranty (whichever occurs first). All GM Performance Parts components carry a 12-month / 12,000-mile warranty.

Enthusiasts who crave the latest technology, maximum horsepower and the expertise and confidence backed by GM can purchase GMPP crate engines, blocks, heads and components from GMPP Authorized Center dealers or any other GM dealership nationwide. For more information or to locate the closest GM dealership visit [Only registered and activated users can see links. ].