ACL Main Bearing Race Series Set - Standard Clearance These bearings are the real deal coated bearings. Not just spray painted OEM bearings, these start as premium ACL brand race bearings. These base bearing shells feature a hardened steel backing, with increased bearing crush for better bearing shell retetion (less likely to spin). They have increased ovality to compensate for rod distortion at high rpm levels, and are designed with a high strength overlay plate for maximum fatigue resistance. All of this is covered up with a professionally applied coating by Calico, giving a truely high performance bearing from the coating all the way to the outer shell. These really are the real deal! This set include 6 bearings with oil grooves, and 4 without. The #4 journal will receive the oil groove on both sides of the journal, the rest have a grooved bearing on the block side only.