RameyRacing Built and CNC Ported Cylinder Head – for Mercury© 450/500R

Performance Cylinder Head Package – Mercury 450R

Engineered for maximum airflow, durability, and consistency, this Performance Cylinder Head Package for the Mercury 450R is built to support serious power and high-RPM operation.

Each cylinder head is fully disassembled, cleaned, and precision-machined before undergoing advanced 5-axis CNC porting to optimize airflow and efficiency. Custom bronze valve guides are installed for improved durability and stability under extreme heat and load.

The valve train is upgraded with a 4 Piston Racing valve spring, retainer, and lock kit to ensure reliable valve control at elevated RPM levels. New OEM valve seals are installed, followed by a precision valve job and resurfacing to ensure proper sealing and surface finish.

Final assembly includes new shim buckets with valve lash set to exact specifications, delivering a complete, ready-to-run cylinder head built for performance and reliability.

Features:

• Full disassembly, cleaning, and inspection

• 5-axis CNC porting for optimized airflow

• Custom bronze valve guides for increased durability

• 4 Piston Racing valve spring, retainer, and lock kit

• New OEM valve seals

• Precision valve job and resurfacing

• New shim buckets with valve lash set

• Ready-to-install performance cylinder head

Built to move more air, handle more RPM, and support serious power — this is the cylinder head your 450R needs to perform at the next level.