Yes KB's want .0065 per inch of bore for the top ring. On the 2nd ring KB wants regular which old school was .003" per inch of bore which was used for decades then lately there was a school of thought that the 2nd ring needed more gap to let gasses that make it pass the 1st ring to escape so people were saying .004" per inch. Myself on I go w KB on the top ring and stay with the tried and true .003 on the 2nd ring. Alot of people use a larger (.004 per inch) gap on the 2nd ring gap but I do not. I gap the same way I do on solids ie for specified .025", a .024 gauge held square has no drag and a .026" has slight drag but it's not a dealbreaker