Engines and Components› Pistons and Piston Rings

United Engine & Machine Co

1 SET KB350.STD/1 SET 4125AM8.STD

$567.56

SKU: U00B KB350KTM.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

Keith Black Hypereutectic pistons are designed for high performance marine, drag race, circle track, street or towing application builds. Made from low expansion 390 alloy with 16 percent silicon, these pistons allow for a tighter piston to wall running clearance. Features include fully machined heads and valve reliefs, triple spiral lock rings, CNC machined pin bores, and an accumulator groove for improved compression ring seal. Wrist pins and spiral locks are included, but piston rings are sold separately.

Fitment

Fitment Guaranteed

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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 KB350KTM.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.

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