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United Engine & Machine Co

KB HYP PISTON KIT BBC 489

$634.36

SKU: U00B KB397KTD.070

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$100 Minimum Order
Non-Returnable Item
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Overview

The KB Performance Hyper Piston and Ring Kit is a set of eight pistons and rings designed for Chevrolet Big Block engines. These pistons are cast from a 390 hypereutectic alloy and heat-treated to T-6 standards for increased strength. They feature fully machined crowns and valve pockets, with a solid dome design and a bore size of 4.320 inches. The lightweight nature of these hypereutectic pistons aims to improve throttle response and RPM changes while maintaining durability under high compression and temperatures.

The included ring set features top rings made from ductile iron with a plasma-moly coating, second rings of iron with a cast iron facing, and stainless steel oil rings. The kit includes wrist pins and retainers, with wrist pins designed for press-fit or floating installation. This piston and ring kit is suitable for a variety of applications, including street, towing, marine, and racing.
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KB HYP PISTON KIT BBC 489

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

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Specifications

BrandUnited Engine & Machine Co
Part NumberU00B KB397KTD.070
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(760) 282-4645 hello@motormia.co

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Returns & Fitment

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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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

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