13in Smooth Overflow Tank

The 13in Smooth Overflow Tank from Billet Specialties is an essential cooling system component for serious automotive enthusiasts and custom builders. This overflow tank serves as the pressure relief and recovery vessel for your engine's coolant system, capturing excess coolant as it expands under operating temperature and returning it to the radiator as the engine cools. Whether you're building a high-performance street machine, a show vehicle, or restoring a classic with modern cooling upgrades, a quality overflow tank prevents coolant loss, maintains proper system pressure, and adds a polished finishing touch to your engine bay.

Billet Specialties engineered this 13-inch tank with a smooth, seamless exterior finish that complements any custom cooling system aesthetic. The compact yet functional design accommodates standard hose connections while the polished aluminum or billet construction resists corrosion and thermal stress that plagues conventional plastic reservoirs. At just 2.39 lbs, it adds minimal weight while providing superior durability compared to factory plastic tanks that degrade under sustained heat cycles and UV exposure—a critical factor when running higher coolant temperatures or extended track sessions.

This overflow tank works with most aftermarket cooling system configurations, including custom radiator builds, electric fan conversions, and engine swaps where factory overflow components don't fit the revised layout. The 19.6-inch length allows flexible mounting in tight engine bays or cleanly integrated into fender wells. Experienced builders and mechanics choose Billet Specialties overflow tanks when appearance and reliability matter equally—ideal for show-quality builds, vintage restorations, and performance platforms where standard plastic reservoirs compromise both function and visual impact. Installation is straightforward with standard radiator hose barb connections.