I couldn't say how much. but sure - that's the whole point of engine break in and why if the rings don't conform to the cylinders in break in you end up pulling it all apart and fixing it. But if this can account for all the leak down is another question. I personally would be leery of a re-ring job that didn't clean the pistons any better than what I see on the piston domes. Considering it's an an original block for your car, I wouldn't chance it.