408BOOSTLB High Performance Base Engine GM LQ4 408ci 550HP / 535TQ - Long Block

Name: 408BOOSTLB High Performance Base Engine GM LQ4 408ci 550HP / 535TQ - Long Block
Brand: ATK ENGINES
SKU: 059-408BOOSTLB
Price: 9458.05 USD
Availability: InStock

^$9,458⁰⁵

Core Charge: ^$370⁰⁰

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Ships on 09/08/2026

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Base Engine

High Performance Base Engine

GM LQ4 408ci

550HP / 535TQ

Long Block

Boost Ready

Cast Iron

Base Engine

ATK Engines 408BOOSTLB Features:

ATK Core Return Process
JEGS and ATK appreciate your business and want to ensure that your core return is as smooth as possible.

Please CLICK HERE for ATK Core Return Process

ATK Engines 408BOOSTLB Engine Specifications:

This engine was designed to be used with a Turbo or Supercharger up to 15psi. We designed this engine to be affordable yet strong enough to handle a good amount of boost!

Horsepower: 550 hp
Torque: 535 lb/ft

ATK Engines 408BOOSTLB Block Information:

GM 6.0L Iron LQ4 with ARP main studs
Bore/Stroke: 4.030 in. x 4.000 in.
Displacement: 408ci

ATK Engines 408BOOSTLB Rotating Assembly:

Crankshaft: Manley 4.000 in. Stroke Internally Balanced 24 tooth Reluctor wheel
Rods: Manley 4340 Forged 6.125 in. H Beam with ARP 2000 Bolts
Compression Ratio: 10.2:1
Pistons: Forged
Rings: Total Seal CS/AP With Steel Top Ring

ATK Engines 408BOOSTLB Camshaft Specs:

Camshaft: Hydraulic roller
Cam Duration @ .050 in. : Intake 226 / Exhaust 230
Cam Lift: Intake .600 in. / Exhaust .575 in.
Lobe Separation Angle: 113lsa

ATK Engines 408BOOSTLB Cylinder Head Information:

Cylinder Heads: ATK LS3
Combustion Chamber Size: 68cc
Intake Runner Size: 260cc
Valve Size: 2.165 in. Intake / 1.590 in. Exhaust
Rocker Arms: OE powdered metal 1.7 ratio with Trunnion Upgrade

ATK Engines 408BOOSTLB Recommended Components:

Oil: 10W30
Oil Filter: Wix
Fuel System: OE EFI System or Aftermarket
Intake: Stock Fuel Injected or Aftermarket
Balancer: Stock Internally Balanced
Flex plate/Flywheel: Stock Internally Balanced
Timing: Set to Factory Specifications Via PCM Module (Tune Required)
Spark Plug: NGK BR7
Tuning: Chassis dyno tune required
Firing Order: Stock
Fuel: 91+ Octane
Recommended Stall Converter: 2800+ based on application
Headers: 1 7/8 in. + depending on application

ATK Engines 408BOOSTLB Notes:

This engine is designed for mild forced induction applications up to 15PSI

Emissions Note:

This part is only legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles or on vehicles used solely for the purposes of closed competition racing.

CLICK THIS LINK FOR IMPORTANT CARB & EPA EMISSIONS INFORMATION ABOUT THIS PART

Please CLICK HERE for ATK Warranty

Part TypeEngine

BrandATK ENGINES

Package Height27.5

Package Width30.0

Package Length35.25

Weight365.0 PG

Part CategoryPerformance Parts

Spark Plug Wires IncludedNo

Engine Block MaterialCast Iron

Air Cleaner IncludedNo