One reason that I end up with custom bore sizes is due to ring selection. If you talk to the piston manufacturers, they'll tell you that it is getting increasingly hard to find quality high performance ring packs in smaller bore sizes - unless they go to metric. So now days I determine the rings I'm going to run FIRST, then use that decision to determine my bore size. Kind of bass-akwards from the old days . . .
Again, this is important in higher performance and race applications - really not an issue for a basic street engine . . . but it is always good to know what your options are. We all determine what we want to spend our money on - and for what reasons. I tend to drift towards overkill - just the way I am wired.
