Filler Cap Polished with Weld-In Alum Bung Large

The Filler Cap Polished with Weld-In Aluminum Bung Large from Allstar Performance is purpose-built for custom fuel system fabrication in high-performance vehicles, race cars, and restomod projects. This component serves as the mounting interface between your fuel tank and cap assembly, providing both structural integrity and a clean, professional appearance. Whether you're building a vintage hot rod, a street machine, or a competition vehicle, this weld-in bung eliminates the need for temporary or aftermarket fuel access solutions and gives you complete control over fuel system aesthetics and function.

Constructed from durable aluminum with a polished finish, the weld-in bung accepts the large-diameter filler cap and integrates directly into your custom fuel tank through welding. The polished aluminum surface resists corrosion and provides a professional, factory-quality look that complements modern and classic vehicle builds alike. The large format accommodates standard fuel filler neck diameters and ensures secure, leak-free operation under normal and performance driving conditions. This design eliminates rattling and improves overall fuel system reliability by providing a rigid, permanent mounting solution rather than relying on press-fit or threaded connections that can loosen over time.

Serious fabricators and DIY builders choose this bung when customizing fuel tank placement or upgrading fuel system infrastructure. It's ideal for welded steel or aluminum fuel tank projects where you need a seamless, professional-grade connection point. Installation requires basic welding equipment and skills; the bung is designed to be tack-welded into position, then fully welded around the perimeter for maximum strength. Compatible with most universal fuel cap designs, this component represents an investment in durability and clean craftsmanship that pays dividends in reliability and appearance.