Aluminum Weld In Bung Large

The Allstar Performance Aluminum Weld In Bung Large (ALL 99373) is a threaded filler bung designed for welding directly into fuel tanks, coolant reservoirs, and fluid containment systems in high-performance vehicles and engines. This 3.000-inch inside diameter aluminum bung provides a secure, permanent mounting point for filler caps, level senders, and fluid access ports on custom and performance applications where reliability and corrosion resistance are essential.

Constructed from natural aluminum, this weld-in bung offers superior corrosion resistance compared to steel alternatives, making it ideal for use in aggressive environments including saltwater cooling systems, fuel tank builds, and custom reservoirs. The threaded design accommodates standard cap and sender fittings, eliminating the need for secondary adapter components. Its universal fit profile integrates seamlessly into custom fabrication projects where OEM bungs are unavailable or incompatible. The aluminum construction remains lightweight while maintaining full structural integrity under pressure and temperature cycling common in performance engine builds.

This product serves fabricators, engine builders, and performance shops performing custom tank and reservoir construction. Whether upgrading a vintage hot rod with modern fuel system components, building a custom coolant recovery tank, or fabricating specialized fluid containment for motorsports applications, the Allstar Performance weld-in bung eliminates fitment uncertainty. The 3.000-inch diameter balances adequate flow capacity with compact installation geometry, accommodating most aftermarket filler caps and sensor fittings without additional machining.

Allstar Performance specializes in custom tank and reservoir components for racing and performance applications. The weld-in design eliminates potential leak points associated with epoxied or bonded bungs, providing a permanent solution suitable for high-vibration and high-temperature engine compartments. Each bung ships as a single unit ready for immediate integration into welding projects.