C.A.T. main bearing caps are manufactured from billet steel with CNC machine finishing on bore and bolt holes for accurate positioning. C.A.T. main caps either for OEM replacement or conversion a original 2 bolts main to 4 bolts the increasing of material strength will reinforce the Capture Strength of main caps to withstand huge simultaneously impact force and higher momentun strength form cylinder explosion by muscle up the engine. Anodized surfaces resist rust for extend useful life. These billet steel caps are for racing applications.