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ATK ENGINES

LS 408CI SHORTBLOCK

$6,180.98

SKU: A040 SP31

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Description

The ATK SP31-G4 LS 408CI Stroker Short Block is designed for high-performance applications, featuring a seasoned 6.0L Iron Gen IV block with a 4.030” x 4.000” bore/stroke, resulting in a 408 cubic inch displacement. It includes a Manley 4340 forged crankshaft with a 58 tooth reluctor wheel, Manley 4340 forged H beam 6.125” rods with ARP 8740 bolts, and Manley 2618 forged -18cc dished, moly skirt coated pistons. This short block offers compression ratios of 10.2:1 (64cc heads), 9.9:1 (68cc heads), and 9.5:1 (72cc heads).

Fitment

Fitment Guaranteed

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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.

Available on iOS & Android

Specifications

BrandATK ENGINES
Part NumberA040 SP31

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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