Exterior Components› Body Panels and Components

Sun Coast Converters

Suncoast Converters Boost Valve Kit - Largest OE Ratio (.489 Dia) 28999-01K

$73.46

SKU: S02K 28999-01K

In Stock
In Stock
Ships by Jun 14
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Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Description

The Sonnax boost valve kit 28999-01K is a performance component designed for GM Powerglide automatic transmissions. This kit addresses wear in the OE boost sleeve, which can cause leakage, reduced line pressure, and instability. The Sonnax kit features the largest factory size valve at .489" diameter and has lengthened critical spool diameters for improved hydraulic sealing.

Fitment

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Specifications

BrandSun Coast Converters
Part NumberS02K 28999-01K

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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