If you are building an all out performance engine, these are the rods you need! Empi Pro Series Rods are made from 4340 Chromoly steel and deliver the reliability required for boost, nitrous and/or high RPM range. This makes these rods lighter and stronger than any of the current H beam or I beam rods available. Every rod is CNC machined, micro polished, stress relieved and finish honed to exacting tolerances. Engineered rod caps help reduce the amount of clearancing required on stroker applications. All rods are held together by forged ARP2000 5/16" bolts capable of withstanding a 220,000 psi tensile load.