I'm assuming you mean the pistons themselves? If so then of course it's always best they go back where they were but at this point doesn't seem that's an option for you. Just a little tip for any future teardown you may do, get yourself a little cheap engraving gun and lightly mark everything as u take out apart in a spot that it isn't gonna hurt anything. I remember as a kid playing with the number punch set my dad had in his toolbox for marking the piston rod caps as he tore down engines but I found the embracing gun is a little easier in a lot of situations.