The machine shop says this is nothing to worry about, and that they can just be sanded down. However, these scratches on the main caps are directly in line with the cylinders. In other words, they are the spots that will receive the blunt of the blow when the cylinders fire. This is probably not the best place to have a low spot (ie a void) under your mains. Should I take my block to a different shop and have it align bored to correct this (which would also allow me to run ARP main studs!)?