Manifold Filler Neck Kit - Billet Alum. Black

The Manifold Filler Neck Kit - Billet Alum. Black from MOROSO is a precision-engineered water neck assembly purpose-built for serious small-block Chevy V8 builders and restoration enthusiasts. This component replaces the factory filler neck and provides a clean, customizable mounting solution for coolant cap placement on high-performance and modified engines. Whether you're designing a custom cooling system, building a street engine, or executing a period-correct restoration, a quality billet aluminum filler neck kit eliminates the limitations of cast OEM designs and integrates seamlessly into contemporary engine bay layouts.

Machined from billet aluminum and finished in black anodize, the Manifold Filler Neck Kit features a 90-degree orientation with a 3-1/4 inch overall height—ideal for tight engine compartments and custom radiator configurations. The assembly includes a filler cap port, 16 AN adapter port for braided hose connections, a 1/2 inch NPT port for thermostat housing or coolant sensor integration, and dual 1/4 inch NPT female ports for overflow, vent lines, or additional accessories. Black anodize finishing resists corrosion while delivering a modern aesthetic that complements both vintage and contemporary engine builds. The compact 4.3 x 4.3 x 5.6 inch footprint and lightweight 1.75 lbs design minimize installation complexity without sacrificing durability or flow capacity.

This filler neck kit is ideal for Chevy small-block V8 applications—including 350, 383, and 454 engine swaps—where stock cooling system geometry won't accommodate modern radiators or custom engine positioning. Fabricators, race teams, and engine builders rely on MOROSO's billet water neck kits to standardize coolant plumbing across multiple projects and reduce fitment variables. Installation requires basic mechanical knowledge and standard AN wrench sizes; the multiple NPT ports support both factory-style overflow tanks and modern catch-can systems. Compatible with most universal radiators and flexible hose routing, this kit transforms a potential cooling system bottleneck into a professional, adaptable junction point for any serious V8 platform.