RameyRacing Mercury 450R Stage 3

Stage Three Engine Rebuild Package

Maximum Output. No Compromises. 

Stage Three is the pinnacle of our engine rebuild lineup — a no-holds-barred performance package for those who want to squeeze every ounce of power from their setup. Built on the proven foundation of our Stage One and Stage Two upgrades, Stage Three adds race-proven headwork, increased compression, and the flexibility of an E85 setup to push your engine into elite territory.

What’s Included – Full Package

Stage Three Upgrades

Diamond High Compression Forged Pistons: Engineered for maximum power and throttle response — perfect for high-boost or naturally aspirated high-RPM applications. Increased compression ratio provides improved efficiency and torque.

CNC Ported Cylinder Heads; Digitally optimized for peak flow and performance — enhanced intake and exhaust flow dramatically improve power across the rev range.

Optional E85 Performance Tune: Take full advantage of E85’s cooling effect and higher octane with a dedicated tune. Expect more aggressive ignition timing, more boost (if applicable), and significantly more power — all while keeping the engine safe under extreme conditions.

Note: E85 tune requires compatible fuel system and injectors. We can supply and install upon request.

From Stage One:

• RameyRacing Connecting Rods
• Diamond Forged Pistons
• ACL Race Bearings
• Cometic Gaskets & P1 Fasteners
• Full block machining: Disassembly, ultrasonic cleaning, decking, boring (+0.25mm), and diamond honing
• Cylinder head service: Cleaning, valve job, and resurfacing

From Stage Two:

• Supercharger Pulley Set
• MoTeC M150 ECU Kit (full programmable ECU)
• Ferrea Valve Springs & Retainers