Exterior Components› Body Panels and Components

United Engine & Machine Co

CHEVROLET 400 ROD 5.700 FLAT TOP +7CC 2V KB HYPER PISTON SET

$74.44

SKU: U00B KB139.040

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Description

The United Engine & Machine Co KB139.040 is a set of 8 hypereutectic aluminum pistons designed for performance applications. These pistons feature a flat top with two valve reliefs and a 4.165-inch bore. They are constructed from 390 aluminum alloy and heat-treated to T6 standards, offering 30 percent greater strength than untreated hypereutectics.

The pistons include 1/16 in., 1/16 in., and 3/16 in. ring grooves. They utilize a lightweight, rigid-rib skirt design for stability and have a 9.025-inch deck height. Designed for Chevy small block Gen I V8 engines, specifically the 6.6L/400, these pistons are compatible with models from 1970 to 1980.

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Specifications

BrandUnited Engine & Machine Co
Part NumberU00B KB139.040

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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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