The year was 1969, and the musclecar wars were in full swing. Each one of the big three had developed their own version of the ultimate high performance big-block engine. Then, GM unleashed the ZL1, the most powerful engine ever released by General Motors. Based on an exotic aluminum block, the ZL1 offered only the best components from the L88 engine including a high compression piston, high flow aluminum heads and intake, and a bombproof bottom end. To celebrate the 50th anniversary of the Chevrolet big-block, GM Performance Parts has brought back a modern version of the ZL1 for your chance to relive musclecar history.
The Anniversary Edition 427 starts with the ZL1 aluminum block using the tooling that helped create this legend in 1969. The block offers a full-strength structure, thick deck surfaces and 4-bolt mains. Building on that foundation, the short block contains a forged steel crank, forged steel rods, and forged aluminum pistons for a 10.1:1 final compression ratio. Aluminum oval-port heads and matching high-flow aluminum oval-port intake are paired with an 870-cfm carburetor. The camshaft is a hydraulic roller with valve lift number of .510" on the intake and .540" on the exhaust. We even added 1.7:1 aluminum roller rockers. Like the original ZL1, the Anniversary 427 comes grossly underrated at 430 horsepower.
Once you purchase an Anniversary 427 big-block crate engine, you enter a very exclusive club because only 427 of these engines will ever be produced. A special owner's kit includes official Anniversary 427 emblems to place on your car, as well as an engine data plaque and certificate of authenticity that share a matching serial number with the valve covers.
Only 427 of these crate engines will ever be produced, and then the ZL1 tooling will be retired forever.
Power: 430 HP @ 5800 RPM, 444 ft. lbs. of torque @ 3800 RPM
Displacement: 427 CID
Bore x Stroke: 4.250” x 3.750”
Compression Ratio: 10.1:1
Recommended Fuel: 92 Octane
Block: Cast Aluminum, 1 piece rear seal, 4-bolt main caps.
Crankshaft: Forged Steel
Connecting Rods: Forged Steel
Pistons: Forged Aluminum
Camshaft: Steel Hydraulic Roller Tappet
Cam Lift: .527” Intake / .544” exhaust
Cam Duration @ .050”: 224 deg. Intake / 234 deg. Exhaust
Lobe Separation: N/A
Cylinder Heads: Aluminum Oval Port.
Combustion Chamber: 110cc
Valves: 2.190” Intake/ 1.880” Exhaust
Rocker Arms: Aluminum Roller, 1.7:1 Ratio
Maximum GM Recommended RPM: 6400
Ignition Timing: Base 10 degrees BTDC, 36 degrees total
• Fully GM assembled long block
• Cast Aluminum Valve Covers with 427 Logo
• Oil pump, pick-up and oil pan
• Aluminum Performance Intake
• GM Tuned Holley 870CFM, vacuum secondaries, electric choke
• HEI Distributor and Spark Plugs
• 14” Auto Trans Flexplate
• 8” Harmonic Balancer
• Front timing cover
• Cast Aluminum Short Water Pump
• Oil Filter and Adapter
• Passenger Side RH Oil Dipstick and Tube
General Motors limited 2 year / 50,000 mile parts & labor warranty. Click on Document tab above for full details.