Made in USA
High Performance Short Block GM LS 408ci
InfoVehicle Info Needed
ATK ENGINESPART NUMBER: 059-SP40

High Performance Short Block GM LS 408ci

$4,96259
Core Charge: $41000
Truck Freight
ShippingShips on Dec 03, 2026
Lowest PriceLowest Price Guarantee
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This product is currently not available. Please call customer service for assistance at 1-800-345-4545.

Gen III/IV LS 24 Tooth
High Performance Short Block
  • GM LS 408ci Stroker
  • Cast Iron 6.0L LQ4 Block
  • 4340 Forged Crankshaft 24 Tooth
  • 4340 Forged H Beam Rods
  • 2618 Forged Dished Pistons -29cc

    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

    NOTE:

    • Core return can be any Chevy LS 6.0L engine

    This short block is built with lower compression perfect for boost and will handle up to 700hp.

    Block Information:

    • Seasoned OE 2001-2007 GM Cast Iron LQ4 6.0L
    • Bore/Stroke: 4.030" x 4.000"
    • Displacement: 408ci
    • Camshaft Bearings: Installed and clocked to OEM position
    • Freeze Plugs: Installed and sealed
    • Oil Galley Plugs: Installed and sealed

    Rotating Assembly:

    • Crankshaft: Manley 4340 forged 24 tooth reluctor wheel
    • Rods: Manley 4340 forged H beam rods with ARP 8740 bolts
    • Compression Ratio: 64cc= 9.3:1 68cc= 9.0:1 / 72cc= 8.7:1 
    • Pistons: Manley 2618 forged dished -29cc
    • Rings: Plasmamoly

      Recommended Components:

    • Balancer: Internal balance
    • Flexplate/Flywheel: Internal balance
    • Head Gasket: .051" thickness or per application
    • Oil: 10W40 Non synthetic for first 3000 miles
    • Oil Filter: Wix or K&N per application
    • Oil Pump: Melling #689-10295 with high pressure spring

    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 TypeShort Block
    BrandATK ENGINES
    Package Height26.0
    Package Width26.0
    Package Length29.0
    Weight353.0 PG
    Part CategoryPerformance Parts
    QuantitySold individually
    Part FitmentSemi Universal
    Vendor Part NumberSP40
    Package Qty1
    Package TypeEA
    No Questions
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