Mishimoto Aluminum Coolant Fill Neck 42mm CNC Machined for Custom Radiators

Mishimoto Aluminum Coolant Fill Neck — 42mm CNC Machined for Custom Radiators Upgrade your custom aluminum radiator with the Mishimoto 42mm Aluminum Coolant Fill Neck. Precision CNC machined from billet aluminum, this fill neck is built to provide a clean, durable, and professional fill point for custom radiator builds and repairs. Precision construction: CNC machined for exact fit and finish. 42mm diameter: Designed to accept Mishimoto radiator caps for reliable sealing. Weld-ready: Supplied ready to be welded into your custom aluminum radiator or expansion tank. Overflow ready: Includes screw-in nipple for overflow hose connection. Corrosion-resistant: High-quality aluminum resists rust and performs under high heat. Ideal for fabricators, race teams, and DIY enthusiasts, this fill neck delivers a clean mounting point and leak-free performance when installed correctly. Pair it with Mishimoto radiator caps and custom hoses for a complete cooling system solution. Key applications: custom radiators, aluminum expansion tanks, racecars, vintage restorations, and performance builds.