Main Studs??

Clamping force is the same between bolts and studs. The difference is the force you put on the cap from either. Studs can exert a higher force because of the material they are made from and what their yield strength is. Secondly nothing is exact. Torque everything to specifications. If you measure the bores and they are within tolerance, the crush will keep them from spinning as long as you have a cushion of good clean oil. If your main bores are out of alignment, the crank will bind when you mock up and spin the crank. If not let her rip. Period... More important is to have your mains and Torque Plate, with the gasket you will use, torqued with the hardware and torque values you will use in final assembly when you bore and hone the cylinders.