The baffles are accessed by drilling out the two 3/16 rivets toward the rear of the pipes. you can't restrict them because there is 3/4 or so hole straight thru. wrap your fiberglass around the baffle and reinstall using (and only using!) stainless steel 3/16 rivets. do not use the average aluminum ones, as you will end up losing a baffle at a very inopertune time! you may need to persuade the baffle out with a wooden object and a hammer from the header end. good luck...
