I had to work with a couple of blocks lately that the main bores were about .001 big from the factory. I did not want to align hone to get it down to size. Most all the bearings I had in stock and ordered had too much clearance on the mains. I tried the Kings and they came in .001 tighter. They cured the problem with the correct clearance. They offer .001 under mains as well. They were too tight.