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ATK GM Gen III 6.0L 370CI 550HP Base LQ4-LB-1 Engine

Item #22662

ATK GM Gen III 6.0L 370CI 550HP Base LQ4-LB-1 Engine
ATK LQ4-LB-1 GM Gen III 6.0L 370CI Engine Base 550HP
* ** FREE SHIPPING on ATK Engines. This item ships directly from the manufacturer and is not available for store pickup. Some engines are made-to-order or can be backordered. Delivery can be delayed up to 5 to 6 weeks but typically ship within 2 weeks.
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The ATK LQ4-LB-1 GM Gen III 6.0L 370CI 550HP Base is a perfect foundation for building a streetable muscle cars. It provides more than 550 horsepower with huge mid- to upper-end power and a noticeable idle. Use of excellent components and expert construction brings reliability and consistency to this crate engine.

Engine Specifications:

  • Horsepower: 550+
  • Torque: 490+
  • Block: GM 6.0L Iron LQ4 Gen III
  • Bore/Stroke: 4.030 x 3.622
  • Year Range: 2001-2007
  • Displacement: 365CI
  • Crankshaft: ATK Reground 3.622" Stroke Internally Balanced 24 Tooth
  • Connecting Rods: Scat 6.125" Forged I Beams with ARP 8740 Bolts
  • Pistons: Manley 2618 Forged -4cc Flat Top
  • Piston Rings: Moly Rings
  • Compression Ratio: 10.0:1 Compression
  • Camshaft: Hydraulic Roller
  • Camshaft Specifications: 228/234 @50 .604/.604 112LSA
  • Camshaft Bearings: Installed & Clocked to OEM Position
  • Cylinder Heads: New LS3 Aluminum 68cc
  • Rocker Arms: OE Rocker Arms with trunion upgrade
  • Oil Galley Plugs: Installed & Sealed
  • Weight: 412

ATK specializes in muscle. With the highest quality internal parts and Dyno Proven combinations of every engine built, ATK is able to add the most bang for your buck and back it up with an industry leading warranty.

Don't forget the engine paint!
Engine Paint


ATK High Performance GM 370 LQ4 550 HP Stage 1 Long Block Crate Engines


Engine Information:

• Oil: 5W30
• Oil Filter: Wix or K&N Recommended Per Your Application
• Fuel Delivery: OE EFI System With Tune or Carb
• Intake Manifold: Factory LS3
• Fuel Injectors: 36lb for optimal Performance
• Spark Plugs: NGK #3186
• Spark Plug Gap: .035"
• Harmonic Balancer/Damper: Stock Factory Balancer Internally Balanced
• Flex Plate / Flywheel: Stock Internally Balanced
• Tuning: Needs Tune/Preferably Chassis Dyno Tune
• Timing: Set To Factory Specifications Via PCM Module (Tune Required)
• Water Pump: Per Application
• Firing Order: 1 8 7 2 6 5 4 3
• Exhaust: 1 7/8 Headers
• Fuel Pump: Upgraded
• Fuel: 91+ Octane
• Ignition: Coil Packs
• Automatic Transmission Stall Converter: 2500+


Recommended Components:

• Balancer: Stock internal balance/per application
• Intake Manifold: Stock EFI, aftermarket EFI, or carbureted intake
• Flexplate/Flywheel: Stock internal balance
• Fuel Pump: Electric per application
• Fuel Injectors: 36lb injectors
• Spark Plugs: NGK #739-TR5GP
• Spark Plug Wires: Factory
• Water Pump: Per application

Disclaimer: The parts listed are ATK’s recommendations of parts to be used to obtain our power figures listed. Power figures can vary based on parts used by the end user. It is the customer’s responsibility to verify components will work for their application. Some modifications to the vehicle may be required using these and or other aftermarket parts.

Shipping Instructions

Shipping is free and lift gate will be provided.

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