Its AISI 304 stainless steel rings embed into the aluminum head for superior sealing

designed to eliminate the common risks of OEM valve shim failure

Oil Return Block Fitting 10AN [use factory bolt and O-ring]21

and 11340150843

CP-Carrillo Connecting Rod Set, BMW B58 Pro-Xtreme 2020 Its AISI 304 stainless steel5150 AutoSport Pro Xtreme Connecting Rods for BMW B58 Engines Boost your BMW B58 engine with 5150 AutoSport Pro Xtreme Connecting Rods by CP Carrillo. These rods are precision engineered for high horsepower and high RPM applications, ensuring superior durability and reliability for turbocharged builds, drag racing, or street strip use. Product Features and Benefits 2000 HP rating, giving your engine the strength needed to handle extreme performance.