Here's how I did my latest muffler mod. I have been using the husky deflectors to add a second port. But they are expensive,and I'm cheap. I used a piece of 1/2" aluminum electrical conduit as the deflector. I saw mastermind and others using silver solder instead of brazing but I had an oa torch and have been looking for an excuse to learn brazing. The idea of a pipe outlet in front of the cat was 'borrowed' from mastermind . Sure beats trying to cut or drill out the cat. .. So here goes, questions, comments and concerns? I used sketchup to measure the area of the exhaust port. I also made a template of the deflector and used that info to make a template the exact size and shape I wanted. Here's the template, exactly .47 square inches, which when added to the existing outlet gives me a total of 85% of the exhaust port.