This main stud kit includes ---10 studs ---10 parallel ground washers ---10 twelve-point nuts ---moly torque lube ---an instruction sheet ARP recommends studs are over bolts because of the ability to obtain a more accurate torque reading studs provide over bolts. Studs don't twist as they are fastened down. Additionally, because of this there is less force exerted on the thread of the block, which results in increased block life, especially on aluminum blocks. Main stud kit - to bolt the main caps of the crankshaft! ARP main studs eliminate main cap walk, as well as protect the threads of the block. ARP recommends to use main studs over main bolts whenever possible. This is because of the studs ability to provide a more accurate torque reading because studs don't twist in the block as they are torqued down.