Thermostat Housing -20AN Straight Up Chevy Black

The Thermostat Housing -20AN Straight Up Chevy Black from Billet Specialties is a precision-engineered water neck designed for Small Block Chevy engines requiring custom cooling system routing. This component serves as the mounting point where your upper radiator hose connects to the engine block, directing coolant flow while maintaining system integrity under heat and pressure. Custom cooling configurations demand a reliable, purpose-built solution, and this straight-up design with 20 AN male inlet provides the exact fitment and flow characteristics serious Chevy builds require for both street and competition applications.

Constructed from lightweight aluminum and finished in black anodize, the Thermostat Housing -20AN Straight Up Chevy Black resists corrosion while maintaining the professional appearance expected in engine bays. The black anodized finish provides both durability and contrast that complements modern engine dress-up packages. Hardware and O-ring are included, eliminating the need for additional sourcing and ensuring proper sealing at the thermostat flange. The straight-up configuration directs coolant vertically, ideal for custom headers, intake manifolds, or tight engine compartment layouts where traditional angled water necks create clearance conflicts.

Engine builders, hot rod enthusiasts, and performance shops standardize on Billet Specialties components for Small Block Chevy restorations and modifications. This thermostat housing excels in custom carbureted engines, EFI conversions, and vintage race builds where radiator hose routing demands flexibility. The 20 AN male connection accepts standard automotive -20 hose fittings, ensuring compatibility with modern plumbing standards. Installation is straightforward—mount to the engine block where the original thermostat housing sits, torque fasteners to specification, and secure your radiator hose with appropriate clamps for reliable long-term service.