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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.

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.

COMPLETE YOUR PERFECT BUILD

OFFER VALID 1/1/23 TO 12/31/23.

$250 rebate on the purchase of a Chevrolet Performance Transmission within 180 days of the purchase of any Chevrolet Performance Crate Engine

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

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

PROPOSITION 65 WARNING.
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PROPOSITION 65 WARNING.
Click for more details.

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 inconel 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

Mobil 1 is now The Official Motor Oil of Chevrolet Performance.

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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.