Filler Neck Block-Off Plate

The Filler Neck Block-Off Plate from MOROSO is a precision aluminum component engineered for Chevy V6 and V8 engine builders who need to seal or eliminate water neck openings during engine modifications or custom cooling system configurations. This block-off plate serves as a clean, reliable solution when factory coolant passages require closure, making it essential for stroker builds, engine swaps, or systems running alternative cooling architectures. At 1/4 inch thick, the plate provides robust structural integrity while maintaining a compact, unobtrusive profile under the hood.

Manufactured from high-quality aluminum in natural finish, the Filler Neck Block-Off Plate offers corrosion resistance and lightweight performance—critical factors in engine bays where thermal cycling and coolant exposure occur regularly. The 1/4 inch thickness ensures the plate won't flex or warp under pressure, maintaining a reliable seal throughout extended engine operation. Its dimensional precision (5.4 x 1.55 x 7.2 inches) allows for direct fitment on compatible Chevrolet V6 and V8 blocks without modification, and the aluminum construction eliminates the weight penalty of cast iron alternatives while delivering superior durability.

Engine builders, hot rod enthusiasts, and performance shops rely on this block-off plate when fabricating custom cooling systems or closing unnecessary factory passages. It integrates seamlessly into high-performance builds where every detail impacts reliability and aesthetics. Installation is straightforward—simply position the plate against the water neck opening and secure with appropriate fasteners compatible with your specific Chevrolet engine platform. Whether you're running a classic small-block 350, a modern LS variant, or a stroked big-block configuration, this MOROSO component delivers the precision fit and durability serious builders demand. Verify fitment with your specific engine block and cooling system layout before ordering.