Originally Posted by Turbo Zetec

cranks are measured for straightness on the mains, you usually set the ends up perfectly on the grinder and then run along all of the mains to measure for any bends. 2 thou is fine to grind out really though, it may have a minute effect on piston heights depending on what type of grinder was used, but nothing to worry about. 2 thou is about half the thickness of a bit of normal printer paper if you need an idea of how bent it was.