Engines and Components› Engines, Blocks and Components

ATK ENGINES

GM 6T70 6SPD

$3,013.89

SKU: A040 8581A-74

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

Advanced — 4+ hours

Description

The ATK ENGINES 8581A-74 (HP74) is a Chevy 350 Vortec 1996-2000 Truck Base Engine, rated at 315HP and 400 TQ. It is an upgrade engine for 1996-2000 Chevrolet trucks and SUVs with the 5.7L Vortec (L31) engine, featuring an OE roller block, hypereutectic pistons, and Vortec cast iron cylinder heads. An ECM tune and 1 5/8" headers are required for optimal performance.

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 8581A-74

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.

View Full Return Policy