Engines and Components› Engines, Blocks and Components

ATK ENGINES

LS 408CI SHORT BLOCK

$5,940.10

SKU: A040 SP36

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Special Order
Ships in 4–6 weeks
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Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Advanced — 4+ hours

Description

The ATK SP36-G4 is a performance short block designed for GM Gen IV LS engines, featuring a seasoned 6.0L Iron Gen IV block, 4.030” x 4.000” bore/stroke for a 408 cubic inch displacement. It includes a Manley 4340 forged 58 tooth reluctor wheel crankshaft, Manley 4340 forged H beam 6.125” ARP 8740 bolts connecting rods, and Manley 2618 forged -29cc dished moly skirt coated pistons with Plasmamoly rings.

Fitment

Fitment Guaranteed

Don’t gamble
on fit.

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 SP36

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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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