The Lunati LS Series are designed for the new GM engines. The cranks are made of 4340 Aircraft quality non-twist forgings. This processing uses a double stress-relief process and Plasma Nitrite case hardening, which gives a very hard surface for long bearing and bending fatigue life. The LS series is gun drilled down the center, rod journals are lightened, pin arms are inertia lightened, the trailing edge of counter weight squared, and the contoured wing used to direct the oil away from the rods. All of this gives you superior acceleration, oil control, and durability. All cranks come either rough or finished balanced.