Engines and Components› Cylinder Heads and Components

ENGINEQUEST

GM 3.0L 4Cyl Marine Cylinder Head

$530.09

SKU: EQ-CH181M

In Stock
In Stock
Ships by Sep 9
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Overview

The EngineQuest GM 3.0L 4Cyl Marine Cylinder Head is a cast iron cylinder head designed for marine and industrial applications. It features thicker decks for enhanced strength and a superior port finish for improved flow.
Show original supplier description
The EngineQuest GM 3.0L 4Cyl Marine Cylinder Head (EQ-CH181M) is a robust replacement component crafted from high-grade cast iron, engineered for durability in marine and industrial environments. This cylinder head is built to meet or exceed original equipment manufacturer specifications, ensuring reliable performance. This cylinder head is specifically designed as a direct fit for MerCruiser and OMC marine engines utilizing the 3.0L (181 cubic inch) displacement. According to available information, this head is a direct fit for 1991 and newer models (140hp) and replaces casting #14096620. EngineQuest cylinder heads undergo a rigorous 25-point quality check. It is important to note that guide plates, such as the EngineQuest EQ-GP181M, are sold separately and are essential for keeping the rocker arm from walking off the valve tip. Screwin studs are also sold separately.

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.

Fitment

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Specifications

BrandENGINEQUEST
Part NumberEQ-CH181M
CategoryEngines and Components

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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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