If you’re building around a Honda J Series engine, the factory water neck setup can be limiting once you start customizing. This MMS Billet Water Neck is designed to give you a clean, flexible solution whether you’re running a simple setup or fabricating a full custom cooling system.
Machined from 6061 aluminum, these flanges are built to fit right and seal properly without forcing you into unnecessary modifications. It’s a solid upgrade, especially if you’re running a Honda-to-GM adapter and want to avoid cutting the bellhousing. Whether you use them as-is or build off them, they give you the flexibility to route your cooling system the way you want.
Key features
Billet water neck flange solution for Honda J Series engines
Machined from US-milled 6061 aluminum
Rear flange features integrated O-ring groove
Front flange retains OEM gasket design
Water crossover tube mount accepts OEM O-ring (rear)
Converts to -16 ORB port on front side
Designed for custom cooling system flexibility
Compatible with Honda to GM adapter setups without bellhousing modification
tips & Notes
Can be used as a direct solution or for custom fabrication setups
Available with or without fittings (select at checkout)
Designed for clean integration with OEM sealing surfaces
Ideal for custom builds requiring upgraded cooling routing
Made in the USA
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