In most cases, I'd agree, Dick. A big muffler, with free-flowing characteristics, will help give you a slight boost over a non-tuned diverter or more restrictive muffler. But, in this case, when setting up the header length, I started at 10" of headers and then gained 600 rpm over the course of shortening the headers down to 2.5". Anything over 6" of header and the power was down dramatically from even "Diverter" rpm figures, showing a lack of tuning from the setup. As the length lessened even further it became necessary to start richening the mixture, to the tune of about 1/2 turn richer, showing that the exhaust side was starting to do it's job and boost power. Similar testing with other canisters of the same theoretical "tuned" length of header and canister showed no boost, giving credence to there being more to it than just a big muffler with short header. The parts all have to work together, otherwise you'll never realize any gains.