[blykins]

It's actually a common way of "customizing" a setup like that. You cut the volume of the piston down, adjust the deck height, and you have higher compression. It's the poor-boy way of doing it. In a world of cheap custom pistons, it's not really viable, but you can make it work.

On a piston with a large bowl shaped dish, the gains in compression would be significant.

Even in a situation where the pistons were at zero deck or below deck, you can get to a spot where the amount of material you're taking off is greater than what you're skimming off the piston, *if* the shape of the piston "volume" is conducive to that.

Most piston volumes are not "straight-walled" cylinders of volume. If you look at them closely, they have taper to them, or a "bowl" setup, where if you start whacking off the top, you really start making gains.

You are correct, I'm speaking in generalities, simply because the same principle can't be applied to every single circumstance out there.