ZRP Std intake valves with black nitride finish for BMW 3.0L B58

K1 forged connecting rods and crankshafts are manufactured from the highest quality 4340 steel. Thanks to years of experience in design and production, these are very high-quality products available at an affordable price. K1 Technologies products are manufactured with extreme precision (bearing bore tolerances are held to +/-0.0001") meeting the high demands of racing and rallying. Only ARP bolts are used (ARP 2000 as standard and 625 plus bolt upgrades as an option). Bronze bushings reduce friction and contribute to a longer service life. Press-fit pins are available in some rod sizes. All connecting rods are 100% designed, finished, and inspected in the USA. All K1 Technologies crankshafts are made from 4340 steel and have hardened cores for greater tensile strength. The bearing surfaces are polished and nitrided for increased wear resistance. ARP bolts are installed and tightened to exact specifications before honing to ensure precise and repeatable bore geometry. All K1 Technologies connecting rods are honed at the manufacturer's facility. K1 Technologies connecting rods are weight-matched in sets and boxed, with weights (rotating, reciprocating, and total) marked to facilitate the balancing process. Product available to order.