Nobody hear can answer that question. You need to load the block in question up and take it to the machine shop. He can check the block out and tell you if it's any good. If it is at .030 now, the next step would be .040 and the .060. He will be able to tell how much is needed when he checks the block out.
I have a .060 overbore in my blown 388ci SBC no problems yet. I rana .040 over 385 for years no problem. It all depends on the block you have. Since they are cast and some have core shift, not all blocks are created equal. If you have a good casting going .040 or .060 over is not an issue.