Exterior Components› Body Panels and Components

United Engine & Machine Co

CHEVROLET 377/400 ROD 5.7/5.565 FLAT TOP +7CC 2V KB HYPER PISTON SET

$74.36

SKU: U00B KB172.STD

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

Advanced — 4+ hours

Description

These hypereutectic aluminum pistons feature a flat top with two valve reliefs and a 4.125 in. bore. They are sold as a set of 8 and include wrist pins and retainers.

These pistons are recommended for Chevy small block Gen I engines, specifically 6.6L/400 CID engines from 1970-1980. They can also be used on 377 CID engines with specific crankshaft, rod length, stroke, and deck height configurations.

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

BrandUnited Engine & Machine Co
Part NumberU00B KB172.STD

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