4G63 Evo 6-9 - Billet Upper Water Neck
 
Your OEM neck is a liability. We built the replacement.
 
The factory 4G63 water neck is a thin, brittle piece of cast garbage that cracks, leaks, and gives you zero flexibility for a real cooling setup. The Ichiban Engineering 4G63 Evo billet upper water neck ends that problem for good.
 
3D-scanned directly off a genuine Evo head, this isn't a guess-and-check aftermarket part - it's a flawless OEM-style fit machined from 6061-T6 billet aluminum, built to survive conditions that would crack the factory unit in a season.
 
Run it your way. Standard outlet keeps your OEM-style hose setup clean with an internal ORB16 thread. Need more? The AN outlet bolts straight into a -16AN line for a proper race-spec cooling system - no adapters, no compromises.
 
Built into every version: an integrated M12x1.5 temp sensor port, ready for your aftermarket gauge the moment you want it - no drilling, no tapping, no second-guessing your cooling data.
 
This is the neck that should've come from the factory.
 
Key Features
 
3D-Scanned OEM-Style Fit
Designed directly from a genuine Evo head for a fitment nothing else on the market matches.
6061-T6 Billet Aluminum
Built to shrug off heat and pressure that destroys the factory cast unit.
Integrated M12x1.5 Temp Sensor Port
Add a gauge the moment you want one - no extra machining required.
Two Outlet Options
Standard OEM-style hose outlet or direct -16AN for full race plumbing.
Heat-Treated, Corrosion-Resistant Finish
Looks as good in year five as it does on day one.
 
Note: water temperature sensor not included (available as an optional add-on)
 
Stop babying a factory part that was never built to last. Upgrade to billet.
 
⚙️ Confirmed fitment: Evo 6, 7, 8, and 9
📧 For technical questions or custom requests contact sales@ichiban.engineering