Aluminum Weld-In Bung

The aluminum weld-in bung is a purpose-built oil cap replacement designed for General Motors engines across model years 1987–2015. Built for boaters, marine mechanics, and engine builders who demand reliability in high-vibration, saltwater-exposed environments, this weld-on cap solves the problem of securing engine oil passages on custom or modified GM power plants where factory caps no longer fit. Whether you're fabricating a fresh engine block or restoring a vintage marine installation, this aluminum bung provides a permanent, sealed solution that won't corrode or vibrate loose.

Constructed from aluminum alloy, the aluminum weld-in bung is engineered for direct TIG or MIG welding into threaded or smooth boss holes on GM engine blocks. The weld-on design eliminates reliance on fasteners or threaded fittings that can fail under thermal cycling and vibration common in marine duty. At just 0.1 pounds, it adds minimal weight while delivering corrosion resistance superior to steel alternatives in saltwater and freshwater conditions alike. The compact profile (4.4 × 5.9 inches) ensures it fits standard GM oil passage locations without interference from adjacent components or hoses.

This bung is ideal for serious boaters restoring or upgrading GM engines in inboard, outboard, or jet-drive configurations, as well as custom marine builders and hot rod shops working with 1987–2015 GM blocks. Professional installers prefer weld-on caps for their permanence—once welded and heat-treated, there's no cap creep, no leaks, and no maintenance. Proper installation requires oxy-acetylene or electric welding equipment and basic machining knowledge; consult your engine builder or marine mechanic to confirm fitment on your specific block configuration and oil system layout.