they make bearings for .030 under - but most machine shops do not recommend using these. You have a higher chance of spinning a bearing if they get too thick, i think. YOu can polish the rod journals if they are not scored up. A lot of machine shops will give you a stock crank for not too much more dough than it would cost to clean it and grind it anyway. I know my local machine shop usually only charges $20 for a core on a stock 302 - they seem happy to get the labor charges for the grind job, plus they have a bunch of them laying around anyway.