Integrated Engineering 164mmx20mm Forged Rods for the 12V, 2.8L 24V and 3.2 24V VR6 Engines. These rdos are made with 4340 Chrome Moly steel, formed into shape using a 2 piece forging for the highest possible fatigue life. The material is multi-stage heat treated to ensure the highest possible fatigue strength as well as good dimensional stability. This feature ensures that our big ends stay round for a lifetime of bearing trouble free service. Following this pattern of high quality, ARP 2000 rod bolts are standard. One of the hallmarks of a high quality connecting rod is its strength to weight ratio. Anyone can create an extremely strong rod out of a huge chunk of steel. Creating one with a reasonable weight that works well in today's high rpm european applications, and holds up to a lifetime of torture is another story. In order to create this balance of strength and light weight, an H beam design is utlized. The design is validated and optimized using modern CAD drafting and FEA analysis techniques. These techniques ensure the rod is as light and strong as possible.