The Stage III kit will include a complete "bench flowed head" with over sized +2 valves and retainers. Core exchange required see below for details. 

This will include a full port and polish and chamber relief to minimize detonation that would normally attack the chamber edges. This is a great feature for running high compression or forced induction applications.  

Also included is heavier valve springs a custom ground camshaft and 4130 chrome molly push rods for maximum power output with this kit.

This kit has the most powerful package available anywhere! for the RZR - RZRS or Ranger, it has all the features in the previous stage II kit and a 3.90mm Stroked crank, with this crank and the big bore kit it will turn a maximum 8500 RPM's

No one else has a kit that produces this amount of horsepower or RPM, this makes the RZR a 902cc dirt shredding, dune roost-en beast! 

 Note: it is not recommended to run any higher than  8500 max in the RPM range 

"Cylinder Head Core exchange required" : Cost without core add $ 450.00