Building an all-out performance engine? EMPI Pro-Series I-Beam Rods are made from 4340 Chromoly steel, and deliver the reliability required for boost, nitrous and/or I-Beam rods. Every rod is CNC machined, micropolished, stress relieved and finish honed to exacting tolerance. Engineered rod caps help reduce the amount of clearancing required on stroker applications. All held together by forged ARP2000 5/16" bolts capable of withstanding a 220,000psitensile load.