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ATK ENGINES

LS 408CI SHORT BLOCK

$6,180.98

SKU: A040 SP39

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Special Order
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Description

The ATK SP39-G4 is a 408 cubic inch LS stroker short block designed for high-performance applications. It features a seasoned 6.0L Iron Gen IV block, 4.030” bore, 4.000” stroke, Manley 4340 forged crankshaft, Manley 4340 forged H-beam rods with ARP 8740 bolts, and Manley 2618 forged -4cc flat top moly skirt coated pistons. This short block is equipped with a 24-tooth reluctor wheel and is internally balanced. It is designed for all motor builds with higher compression ratios and can handle up to 700 horsepower. It is recommended to use 10W30 non-synthetic oil for the first 3000 miles.

Fitment

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Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

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Specifications

BrandATK ENGINES
Part NumberA040 SP39

Videos

ATK's new LS 408CI Stroker!.AVI

ATK's new LS 408CI Stroker!.AVI
ATK #LS01C LQ4 408CI Stroker 620+HP!

ATK #LS01C LQ4 408CI Stroker 620+HP!
ATK #LS01C Custom LS 408CI Stroker 600+HP!

ATK #LS01C Custom LS 408CI Stroker 600+HP!

Buy with Confidence

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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