Heating and Cooling› Water Pumps

SIERRAMARINE

WATER PUMP

$131.63

SKU: S08C 18-3599-2

In Stock
In Stock
Ships by Jun 15
Free Shipping
Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Easy — 1–2 hours

Description

The Sierra Marine 18-3599-2 is a circulating water pump designed for GM V-6 and small block V-8 engines. This bi-directional pump features a brass impeller and replaces Mercury part 8503991. It is compatible with GM 305, 350, and 377 CID engines, specifically those with stamped steel timing covers.

Fitment

Fitment Guaranteed

Don’t gamble
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 18-3599-2

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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