We recommend using main studs over bolts for most performance build ups for several key reasons. First, because studs provide more accurate torque readings because studs do not have to "twist" into the cylinder block threads, thus all clamping forces are on one axis. Second, because the threads in the block will be under less stress, and because studs will not have to be removed every time during disassembly, the life of the threads in the block will be improved greatly. And lastly, studs on race engines will aid in quicker tear downs and easier reassembly because the studs will locate the caps more accurately then bolts.