To get any kind of a noticeable result, you'd need to take quite a bit off. Which would mean custom length pushrods, and possible intake manifold fitment issues. It's not worth doing. Just live with what you have for now until you can go through it and change the pistons. The pistons in my 69 440HP were sitting .110" down in the hole at TDC. My 2355s are at .005". See what I mean?