Exhaust› Headers, Manifolds and Components

SIERRAMARINE

MANIFOLD

$463.94

SKU: S08C 18-1903

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

Easy — 1–2 hours

Description

The Sierra Marine 18-1903 exhaust manifold is a port side replacement for OMC GM 5.0L & 5.7L marine engines with an end riser. It is made of heavy-duty cast iron, painted black, and includes gaskets and a drain cap. It replaces OMC 912442 and Osco 2442.

Fitment

Fitment Guaranteed

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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

BrandSIERRAMARINE
Part NumberS08C 18-1903

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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