My Account
Shopping Cart

Sierra 18-4387 Overhaul Gasket Set for GM 454 7.4L Big Block Marine Engines

Manufacturer

Sierra

<p>For nearly six decades, Sierra has established itself as one of the marine industry's most trusted names in aftermarket engine and drive parts. Founded as a specialized marine parts manufacturer, Sierra has grown into a comprehensive supplier of replacement components, instrumentation, and accessories for both recreational and commercial boating applications. Operating from their 300,000-square-foot distribution center in Litchfield, Illinois, Sierra serves boat owners and marine technicians worldwide with an extensive catalog of parts engineered specifically for the harsh saltwater environment.</p><h3>Marine Engine Excellence</h3><p>Sierra's reputation was built on delivering precision-engineered internal engine components and drive system parts that meet or exceed OEM specifications. Their <a href="/7570-sierra-engine-gasket-set-5404">engine gasket sets</a> provide critical sealing solutions for inboard and outboard motors, while their <a href="/7570-sierra-engine-complete-assembly-15341">engine complete assemblies</a> offer comprehensive replacement options for major overhauls. Each component undergoes rigorous testing to ensure reliability in demanding marine conditions, from corrosion resistance to temperature cycling performance.</p><h3>Instrumentation and Monitoring Systems</h3><p>Accurate instrumentation is essential for boat operators to monitor engine health and prevent costly breakdowns on the water. Sierra's comprehensive line of <a href="/7570-sierra-gauges-200483">gauges</a> includes everything from fuel pressure and temperature indicators to voltmeters and trim gauges, all designed with marine-grade materials that withstand vibration, moisture, and UV exposure. Their <a href="/7570-sierra-tachometer-gauge-1488">tachometer gauges</a> deliver precise RPM readings critical for optimizing engine performance and fuel efficiency. Supporting these instruments, Sierra's <a href="/7570-sierra-gauge-resistor-47908">gauge resistors</a> ensure proper signal conditioning and accurate readings across various sensor types and engine configurations.</p><h3>Expanded Product Portfolio</h3><p>In 2022, Sierra significantly broadened its scope beyond traditional marine engine parts to encompass a wider range of boating accessories and even outdoor power equipment components. This strategic expansion brought established marine brands like Shields and Moeller under the Sierra umbrella, creating a one-stop resource for marine maintenance and replacement parts. The company now offers fuel systems, electrical components, battery charging solutions, and NMEA electronics alongside their traditional engine parts lineup.</p><h3>Quality Backed by Industry-Leading Warranties</h3><p>What sets Sierra apart in the crowded aftermarket marine parts market is their commitment to standing behind every component they manufacture. Their warranty coverage extends beyond simple part replacement—it includes shop labor, haul-out fees, towing charges, and related incidental costs should a warrantied part fail. This comprehensive protection reflects the company's confidence in their manufacturing processes and quality control standards. For boat owners facing repairs far from shore or mechanics working on customer vessels, this peace of mind is invaluable. Whether you're maintaining an outboard motor, rebuilding an inboard engine, or upgrading your boat's instrumentation, Sierra's decades of marine industry experience and commitment to quality make them a reliable choice for keeping your vessel running at peak performance.</p>

Part Number

18-4387
08/07/2036 6:31 AM
Sale Price

$376.17

1 left at this price

delivery box

Usually delivered within 2 days

free shipping

FREE SHIPPING

Authorize Seller Badge
No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Sierra 18-4387 Overhaul Gasket Set is a comprehensive engine rebuild solution engineered for GM 454 (7.4L) CID oval port big block inboard marine engines. This complete set delivers all the gaskets needed for a thorough engine overhaul, restoring proper sealing and performance to your marine powerplant.

Key Features:

  • Complete overhaul gasket set for GM 454 (7.4L) CID oval port engines
  • Includes Sierra 18-3877 head gasket
  • Manufactured to precise OEM specifications for reliable sealing performance
  • Constructed from high-grade materials for exceptional durability and service life
  • Incorporates the latest manufacturing technologies and design innovations for accurate O.E. fitment

Cross-Reference Part Numbers:

  • Replaces MerCruiser Stern Drive: 27-801853
  • Replaces GLM: 39020
  • Replaces Mallory: 9-61102

Sierra International is a trusted name in marine engine parts, and this overhaul gasket set reflects their commitment to quality. Whether performing a full engine rebuild or a major top-end overhaul, the Sierra 18-4387 provides the complete sealing package needed to get your big block back on the water with confidence.

amazing

good so far.

Thanks

So far so good

Awesome

Great prices and fast shipping

easy

Free shipping and a great price.

Fast Shipping, Great price, Parts were well packed

I was hesitant to order from Autoplicity due to the perception that the price was too good to be real (and not some scam). However, I read a few reviews on the internet and decided to take a chance. Once I placed my order I was sent a tracking number and received my car parts within 2 weeks. I was happy that I got the parts I ordered and the price was really low. Simple and quick.

Great prices

Share icon
Return Policy
Returns are easy at Boatplicity

Not happy with a purchase? No problem. We've made returning items as easy as possible. And most purchases can be returned for free for 30 days. Learn more about our Returns Policy