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L8T CRATE
ENGINE

L8T CRATE ENGINE

QUALITY PARTS.
HIGH-CALIBER BUILD.

Offer Valid 1/1/24 to 12/31/24

$250 rebate* on the purchase of a Chevrolet Performance Transmission within 180 days of the purchase of any Chevrolet Performance Crate Engine**. Rebate amount dependent on the package purchased.

PARTS INTENDED FOR COMPETITION USE ONLY.
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PARTS INTENDED FOR COMPETITION USE ONLY.
Click for more details.

PROPOSITION 65 WARNING.
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PROPOSITION 65 WARNING.
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The heart of the Silverado 2500HD and 3500 HD models

In addition to the complete L8T crate engine, Chevrolet Performance offers the L8T Long Block — the high-output, direct-injected foundation of the Gen V Small Block-based 6.6L engine offered in the Silverado 2500HD and 3500HD models.

PART NO. 19433748

WhyBuy

401 HP @ 5,200 RPM

WhyBuy

464 LB-FT @ 4,000 RPM

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 ration of 10:8:1 in the engine, which contributes to its high output.

Connect & Cruise Powertrain System

Connect & Cruise Crate Powertrain Systems provide factory-matched engine-and-transmission combinations that include specially calibrated controllers and wire harnesses designed for retrofit installations in older vehicles.  

Parts and labor warranty when installed by a GM Dealer or qualified installing independent Service Center (ISC) or when sold over the counter and REPAIRED by a GM Dealer or qualifying ISC. Parts only when consumer repaired or installed in non-highway application. Coverage limited to defects in material and/or workmanship of the specific part only. Warranty valid when all required components are installed on the same vehicle and purchased on one invoice.

††Must be purchased from a participating U.S. dealer or Chevrolet Performance Authorized Reseller. Mail-in rebate offer not available with other offers. See gmpartsrebates.com for details, applicable rebate amounts, and rebate form. Rebates must be submitted by 1/31/25. Rebates may be submitted over two invoices within 120 days of each other. Allow 6 to 8 weeks for delivery of debit card. Offer valid 1/1/24 to 12/31/24.

 

Unless specifically noted to the contrary herein, vehicles equipped with Chevrolet Performance parts that are emissions-related may not meet U.S., Canadian, and state and provincial laws and regulations relating to motor-vehicle emissions. These parts are designed and intended for use in vehicles operated exclusively for competition: in racing or organized competition on courses separate from public streets or highways. Visit www.chevroletperformance.com/emissions for more details. Rebate form and details available at chevrolet.com/performance/offers.

Installation Guides

Find everything from vital data about your engine’s capabilities to how to install it into your build.

L8T Tech Specs

  • Part Number: 19433748
  • Engine Type: Gen V Small Block V-8 direct injection spark ignition
  • Displacement (cu. in.): 400 (6.6L)
  • Bore x Stroke (in / mm): 4.065 x 3.860 (103.25 mm x 98 mm)
  • Block (P/N 19420904): Cast iron with 6-bolt nodular main bearing caps
  • Crankshaft (P/N 12708884): Forged steel
  • Connecting Rods (P/N 12675746): Forged powder-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 hollow intake / 1.590 sodium filled exhaust
  • Compression Ratio: 10.8:1 (nominal)
  • Rocker Arms (P/N 12619829): Investment cast roller trunnion
  • Rocker Arm Ratio: 1.8:1
  • 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 rpm
  • Reluctor wheel: 58X
  • Balanced: Internal
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Unless specifically noted to the contrary herein, vehicles equipped with Chevrolet Performance parts that are emissions-related may not meet U.S., Canadian, and state and provincial laws and regulations relating to motor-vehicle emissions. These parts are designed and intended for use in vehicles operated exclusively for competition: in racing or organized competition on courses separate from public streets or highways. Visit www.chevroletperformance.com/emissions for more details.