19433748 - L8T 6.6L 401 HP Crate Engine by Chevrolet Performance (pre-2024)

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.

INSTALLATION NOTES

• 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

Specifications:
Power: 401 HP @ 5200 RPM, 464 ft. lbs. of torque @ 4000 RPM
Displacement: 400 CID, 6.6L
Bore x Stroke: 4.060” x 3.860”
Compression Ratio: 10.8:1
Recommended Fuel: 87 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: .500” Intake / .492” exhaust
Cam Duration @ .050”: 193 deg. Intake / 199 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: 5600

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

Warranty:
General Motors limited 2 year / 50,000 mile parts & labor warranty. Click on Document tab above for full details.