Actually it DOESN'T matter. What IS important is that you get the correct rod caps on the correct rods.
I would stick each piston in one hole, and measure clearance the same way on each to see if you can determine if any are worn substantially more/ less than the others.
If not, does not matter which hole
If so, mike the bores and try to match the larger pistons with the larger bores.
Again, MAIN thing is that the rod caps are on the correct rods.
