Sierra Distributor Cap 18-5394, Replaces 243658, for GM V-8 New Style Ignition

The Sierra 18-5394 is a marine distributor cap engineered for GM V-8 engines of the new style design, where the ignition module is integrated directly into the cap itself rather than mounted as a separate external component. This module-in-cap construction simplifies the ignition system layout and is specific to the newer GM V-8 configuration it is built for.

The cap uses a twist-on closure for a secure, positive connection to the distributor body, helping keep moisture and contaminants out of the ignition circuit in a marine environment. It measures 4.9 x 5.5 x 3.6 inches and weighs 0.25 pounds. This distributor cap directly replaces OEM part number 243658, making it a straightforward swap for boats and stern drives originally equipped with that component.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-5394
• Product Type: Distributor Cap
• Replaces (OEM): 243658
• Engine Fitment: GM V-8, new style
• Ignition Module: Integrated (Module in Cap)
• Closure Type: Twist-On
• Item Dimensions: 4.9 x 5.5 x 3.6 inches
• Weight: 0.25 pounds
• UPC: 030999319128

Fitment

• GM V-8 engines, new style (module-in-cap design)

Replaces (OEM)

• 243658

Frequently Asked Questions

What engines does the Sierra 18-5394 distributor cap fit? The 18-5394 is built for GM V-8 engines of the new style, where the ignition module is integrated into the cap rather than mounted separately.

What OEM part number does this distributor cap replace? Sierra 18-5394 replaces OEM part number 243658.

What is meant by 'module in cap' for this distributor cap? It means the ignition module is built directly into the distributor cap assembly of the 18-5394, rather than being a separate external module bolted to the distributor housing.

How much does the 18-5394 distributor cap weigh? The Sierra 18-5394 weighs 0.25 pounds.

What are the dimensions of this distributor cap? The 18-5394 measures 4.9 x 5.5 x 3.6 inches.

How does the cap attach to the distributor? It uses a twist-on closure, which secures the 18-5394 cap onto the distributor body.

Is this a genuine Sierra part or aftermarket? The 18-5394 is a Sierra-branded distributor cap sold under Sierra's own part number as a direct replacement for OEM 243658.

What is included when I order this part? Ordering Sierra 18-5394 includes one distributor cap.

Will this cap work with older GM distributor styles? The 18-5394 is designed for the new style GM V-8 distributor with an integrated module, not the older design that uses a separate external module.

Does this distributor cap fit V-6 or only V-8 GM engines? The Sierra 18-5394 is designated for GM V-8 engines.

What is the UPC for the Sierra 18-5394 distributor cap? The UPC for the Sierra 18-5394 distributor cap is 030999319128.