Drivetrain› Automatic Transmissions and Components

Sun Coast Converters

Suncoast Heavy Duty Input Shaft SUNSC-77733-12S

$1,010.00

SKU: S02K SC-77733-12S

In Stock
In Stock
Ships by Jun 10
Free Shipping
Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Description

The SunCoast Performance Heavy Duty Input Shaft (SC-77733-12S), also designated Sonnax 77733-12S, is engineered for GM 4L60-E, 4L65-E, and 4L70-E transmissions (specifically 300mm reluctor-style units). It's designed to prevent input shaft failures in high-horsepower street/strip applications. Constructed from specially heat-treated steel, it has hard outer layers and a ductile inner core for fracture resistance. Features include chamfered feed holes, shot peening, and deep cryogenic treatment for extreme durability.

Fitment

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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.

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Specifications

BrandSun Coast Converters
Part NumberS02K SC-77733-12S

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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