Im getting ready to reinstall my pistons but im not sure of the ring gap. I thought it was .021 for non aspirated however when I checked the old rings they are only like .018 so im kinda hesitant to file the new ones to .021. the engine builder at the place where i bought the rings said as long as the gaps arent less than .014 I should be ok. The new rings (hastings) are close to .018 right out of the box.