When you bore an engine and polish the crank this is not really designed to make more power.. This is to get the block and crank back in rebuildable shape. Now there are a small amount of power that will come from this just simply because the cylinders being alittle larger will make the engine alittle bigger.. However the most power is going to be found because after the rebuild you will have a frsh motor versus a 700,000 mile smoke blower.