Rev 6 remanufactured cylinder head will include: Rev6 upgraded manganese bronze valve guides (retain their size, better heat dissipation and longevity) Upgraded forged one piece nitrated valves (stronger than OEM, better rev count, performance and longevity) High temp, performance valve stem seals Modified cam caps for additional oiling to the top end Rev6 cylinder heads will come complete with cams, shimmed and ready to install! We set all valve lash looser to accommodate for lap in time. This will help reduce the need for shimming after the break-in point. How it works: Order Receive our shipping label & rebuild form via email Put your old cylinder head in a box Ship it with our label and rebuild form Once your cylinder head arrives at Rev6, we will run it through the build process and have it shipped back within 3-4 days of receiving it here. Rev6 offers quality parts that are proven to last.