Chevrolet Performance L8T 6.6L Crate Engine


  • 401 hp @ 5,200 rpm/464 lb.-ft. @ 4,000 rpm
  • Largest Displacement LT-Family Engine
  • Forged Steel Crankshaft
  • Must Use with 6L80 Transmission

Available on backorder

Have your engine dyno tested by one of our professional engine builders to ensure everything is properly broken in. We can dyno your engine with your components to make sure everything is working harmoniously before shipping you the whole assembly drained and ready to install.

Shipping is free, but there is a delivery fee for residential addresses.

This product is not available online. Please call 855-806-1147 to order.

L8T Chevrolet Performance Crate Engine

P/N 19433748

401 hp @ 5,200 rpm / 464 lb.-ft. @ 4,000 rpm

L8T 6.6L Tech Specs:
Part Number: 19433748
Engine Type: Gen V Small Block C-8 direct injection spark ignition
Displacement (cu in): 400 (6.6L)
Bore x Stroke (in): 4.060 x 3.860 (103.25mm x 98mm)
Block (P/N 12619171): Cast iron with 6-bolt nodular main bearing caps
Crankshaft: Forged Steel
Connecting Rods: Forged powdered metal
Pistons (P/N 12699527-R 12699529-L): Hypereutectic aluminum
Camshaft Type (P/N 12672469): Billet steel hydraulic roller
Valve Lift (in): 0.500″ intake / 0.492″ exhaust
Camshaft Duration (@0.050 in): 193° intake / 199° exhaust
Cylinder Heads (P/N 12703610): Aluminum, rectangular port D/I with 59.02cc chambers
Valve Size (in): 2.130″ intake / 1.590″ exhaust
Compression ratio: 10.8:1 (nominal)
Rocker Arms (P/N 12619829): Investment-cast, roller trunnion
Rocker Arm Ratio: 1.81:1
Intake Manifold (P/N 12639087): Composite
Throttle Body (P/N 12730580): 87mm diameter (single-bore)
Fuel Delivery: High-pressure direct injection (2,175 psi/150 bar)
Recommended Fuel: 87 octane
Ignition System: Coil-on-plug
Maximum Recommended RPM: 5600
Reluctor Wheel: 58x
Balanced: Internal

Long Block Version Available Here

Installation Notes:

  • Engines 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
  • Used with Engine Control kit 19433736 (must use 6L80 transmission). Includes programmed controller, wire harness, pedal, oxygen sensors and mounts, MAF, Fuel Line Pressure Sensor, and Fuel Pump Power Module (FPPM).


Weight 425 lbs

L8T Chevrolet Performance Crate Engine

19433748 Chevrolet Motor

Heavy-Duty Power from Chevy’s HD Trucks

With 401 horsepower and 464 lb.-ft. of torque on tap, the L8T crate engine is the
largest-displacement LT-family engine in our lineup, offering plenty of low-rpm
torque. Direct injection offers more precise fuel control than port injection,
enabling a comparatively high compression ratio of 10.8:1 in the engine, which
contributes to its high output.

It’s built with a forged steel crankshaft and other high-strength parts. Additional
features such as oil-spray cooling for the pistons and a cast iron, long-skirt cylinder
block with six-bolt, cross-bolted main caps contribute to the engine’s strength and
durability. Comes with production style exhaust manifolds.

Our L8T crate engine package comes complete from the throttle body to the oil
pan, including the PCV tube, evap tube, oil dipstick and 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.

Chevrolet Performance Crate Engines include a 24-month or 50,000-mile (80,000 kilometer) limited warranty.

Click here for more detailed warranty information.


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Prop65WARNING: These auto parts can expose you to chemicals including phthalates and lead. Installing or using these parts can expose you to other parts containing these chemicals and to engine exhaust, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to

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