Chrysler owner since 1964, never heard of it for any purpose. Never seen or heard of a passenger car piston with an extra ring land.
If someone has an engine to use for test, I need the dome OD (not the bore), B&S, static CR, and how far the top land is moved (up limited by the minimum crown thickness, down limited by proximity to the 2nd ring) to do a calculation of the effect.
Sorry, didn't mean an extra land, what I meant was there were pistons made with the top land in different positions relative to the top of the piston. This affects static compression ratio.
