Thought I'd try to help with numbers... I measured 140db from my header because no one wants to put a muffler on it. I also measured about 4 seconds of smoke in the eyes before all vision is lost. Is that enough numbers? Also- I was just down at Skips' exhaust in Plaistow, NH, he said someone had just stopped by with a D, wanted to know if you were on the list.. that's all. If I get any more numbers, I will post. Jim 1537