I just ordered a set of Supertrapp Fat Shots (model #728-71576) for my 2009 Harley-Davidson Ultra Classic. The bike has a Stage 1 upgrade and I'm replacing a set of high performance mufflers that are just too loud for me. I'm wondering how many discs to start with when I first install them. I want it to be as quiet as possible without hurting the performance I've paid for in my Stage 1 upgrade. I think the installation instructions recommend starting with 10 discs, but the '09 Touring bikes (non-California) did not have a catalytic converter in their stock headers, so that tends to make them a little louder than the '10 and up models. That makes me think 8 or 9 discs might be a better starting point, but I'm hoping to get some guidance from someone with experience in that area. Thanks in advance for the help!