Exterior Components› Body Panels and Components

United Engine & Machine Co

7000 CHEVROLET 454 (V8) ROD 6.135 OC HOLLOW DOME 26CC 1V KB HYPER PISTON SET

$74.83

SKU: U00B KB257.STD

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

Moderate — 2–4 hours

Description

The United Engine & Machine Co KB257.STD is a set of eight hypereutectic aluminum pistons designed for a 4.280-inch bore and a 4.000-inch stroke. These pistons feature a dome style with a single valve relief and a negative 26.00cc piston head volume. They are constructed from hypereutectic aluminum and include press-fit or floating wrist pins.

The pistons have a stock engine stroke type and a rod length of 6.135 inches. The wrist pin diameter is 0.990 inches, and wrist pin retainers are included. The piston ring thickness is specified as 5/64 in. x 5/64 in. x 3/16 in. These pistons are sold as a set of 8.

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 KB257.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