These rods come with WMC H-11 tool steel bolts (equivalent to ARP 2000 rod bolts) or the CAR SPS Bolts (equivalent to ARP625 rod bolts) for high boost and rev applications.Carrillo make the lightest wide H Beam steel connecting rods in the market and 100% made in USA.Every Carrillo connecting rod is a symphony of precision: material specialist, forging precision, production craftsman, design engineers and engine specialists.Carrillo rods are under the control of a rigorous Quality Assurance system. Each Carrillo rod is subjected to a variety of inline quality checks to ensure dimensions and meet stringent tolerance requirements. Carrillo employs a variety of testing equipment to accurately assess these tolerances, including a CMM, Air and Height-Gages and a 2D measuring system to name just a few. The initial quality assurance starts with the selection of steel, followed by a strict forging and a heat treating process.Every connecting rod leaves Carrillos facility with a specification card. This card displays a part number, critical dimensions, weights, job number and bolt installation chart; all for ease of identification and tracking.