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SKU: 19435523

We’ve optimized every cubic inch of our largest-displacement LT engine with the unique L8P performance crate engine. With 523 horsepower and 543 lb.-ft. of torque, this package combines the displacement and heavy-duty strength of our production-based L8T 6.6L engine plus a unique camshaft based off the LT2.

It’s all rooted in the tough foundation of the L8T, with a forged steel crankshaft, high-strength parts, high-flow heads and composite intake manifold. We then add a more performance-oriented valvetrain, including valves, springs, and an LT2- based camshaft. It features more lift and duration to help draw more air and fuel into the engine, which helps build power.

Our L8P crate engine package comes complete from the throttle body to the oil pan, including the PCV tube, evap tube, oil dipstick, oil fill tube and cap. It does not include the controller, harness, oxygen sensors or a Front End Accessory Drive system. See Installation Notes below for recommendations.

• Engine is shipped with high-pressure direct-injection fuel pump installed
• Front End Accessory Drive system must be ordered separately and includes hydraulic power steering, with center pulley. Pulley-mounted fan not recommended
• Use Front End Accessory Drive system P/N 19433745 for applications with air conditioning and Front End Accessory Drive system P/N 19433746 for applications without air conditioning
• Includes 8-bolt flexplate for automatic transmissions
• Use with Engine Control kit 19435524 (must use 6L80-E transmission).

  • Horsepower

    523 HP

  • Torque

    543 LB-FT

  • Tech Specs

    Power: 523HP @ 5800 RPM, 543 ft. lbs. of torque @ 4600 RPM
    Displacement: 400 CID, 6.6L
    Bore x Stroke: 4.060” x 3.860”
    Compression Ratio: 10.8:1
    Recommended Fuel: 91 Octane
    Block: Cast Cast irong with 6 bolt cross bolted main caps
    Crankshaft: 8-bolt Forged Steel
    Connecting Rods: Forged Powdered Metal Steel
    Pistons: Hypereutectic Aluminum
    Camshaft: Billet Steel Hydraulic Roller Tappet
    Cam Lift: .549” Intake / .549” exhaust
    Cam Duration @ .050”: 218 deg. Intake / 231 deg. Exhaust
    Lobe Separation: N/A
    Cylinder Heads: Aluminum Rectangular Port, Direct Injected
    Combustion Chamber: 59cc
    Valves: 2.130” Intake/ 1.590” Exhaust
    Rocker Arms: Cast Roller Trunnion, 1.81:1 Ratio
    Balance: Internal
    Reluctor: 58X
    Maximum GM Recommended RPM: 6000

    Engine Includes:
    • Fully GM assembled long block
    • Ignition Coils, Plug Wires and Spark Plugs
    • Oil pump, pick-up and wet sump oil pan
    • Exhaust Manifolds
    • Intake, Injectors and Throttle Body
    • High Pressure Fuel Pump (installed)
    • 14” Auto Trans Flexplate
    • Harmonic Balancer
    • Front timing cover
    • Aluminum Water Pump
    • Oil Filter
    • Passenger Side RH Oil Dipstick and Tube

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