The factory Porsche Boxster, Cayman, 911 models use connecting rods that are called cracked-cap rods, where the cap is mechanically broken off the connecting rod, the partition line or crack used to locate the cap on the rod as a cost savings measure. Conventional rods use locator bushings and precision ground mating surfaces. Where conventional rods can be reconditioned, cracked-cap rods cannot be rebuilt, only replaced. Due to the excessive cost of original equipment connecting rods and their being prone to rod bolt failures (it's not possible to replace the rod bolts without resizing the rods unfortunately), the best next solution is our new billet r&r pro connecting rods. R&r starts with the highest grades of e4340aq chromoly, exceeding the specifications of 300m steel which is then machined in our state of the art cnc facility. Each and every connecting rod has been engineered for the ultimate balance of strength and weight, heat treated, cryogenically treated, triple tempered, shot-peened, quality tested, and then finally assembled with the finest arp 2000, l19, and custom age 625 fasteners, precision honed, and balanced to industry specification, right out of the box.