GM Performance Crate Engine, L8P Rotating Assembly, 6.6L, 400cid, 523 HP, 10.8:1 Compression, Cast Iron Block, Aluminum Heads, Chevy, GMC, Each (PART #GMP-19435523)

By combining the large-displacement and heavy-duty elements of the L8T 6.6L engine and a unique camshaft based off the Corvette Stingray's high-revving LT2 V-8, GM Performance engineers have created the all-new L8P 400 c.i.d. Performance crate engine. Rated at 523 hp and 543 lbs.-ft. of torque, it offers your project a unique and naturally aspirated combination of big-displacement torque and high-rpm horsepower.

The L8T 6.6L foundation is the same high-strength, big-displacement engine found in the Silverado HD from 2020 to present day, featuring a forged steel crankshaft and high-strength components. Additional features such as oil-spray cooling for the pistons and a cast iron, long-skirt cylinder block with 6-bolt, cross-bolted main caps contribute to the engine's strength and durability.

The new L8P builds on that with a unique, upgraded valvetrain featuring performance-oriented valves and springs, along with a unique camshaft that is based off the Corvette Stingray's LT2 engine. It has a non-active fuel management profile and more duration than the L8t's camshaft. It's the best of both engines: the largest displacement in the LT family and the power-building attributes of the Corvette camshaft. Put it to work in your project.

Fast Facts:

• Displacement: 400 cu. in. (6.6L)
• Bore x Stroke: 4.06 in. x 3.86 in.
• Crankshaft: Forged steel
• Pistons: Hypereutectic aluminum
• Compression ratio: 10.8:1
• Cylinder heads: Rectangular port D/I with 59.02cc chambers
• Camshaft type: Billet steel hydraulic roller
• Camshaft duration: 218 degree intake/231 degree exhaust at .050 in.
• Fuel delivery: Direct injection with high-pressure pump
• Horsepower: 523 at 5,800 rpm
• Torque (lbs.-ft.): 543 at 4,800 rpm
• Engine type: Gen V small block V-8 direct injection spark ignition
• Block: Cast iron with 6-bolt no Dula main bearing caps
• Connecting rods: Forged powder-metal
• Valve lift (in.): 0.549 intake / 0.549 exhaust
• Rocker arms: Investment cast roller trunnion
• Rocker arm ratio: 1.8:1
• Intake manifold: Composite
• Throttle body: 87mm diameter (single-bore)
• Fuel delivery: High-pressure direct injection (2,175 psi / 150 bar)
• Recommended fuel: Premium pump
• Ignition system: Coil-on-plug
• Maximum recommended RPM: 6,000 rpm
• Reluctor wheel: 58X
• Balanced: Internal

• Note:

Use with the new engine control kit, P/N 19435524, which includes a programmed controller, wire harness, pedal, oxygen sensors and mounts, MAD, fuel line pressure sensor and fuel pump power module. Flexplate P/N 12685003 must be purchased for these engines to be compatible with the 10-speed supermatic transmission. 10-speed supermatic transmission uses six bolts to attach the torque converter.