[Dirty Harry]

I also had a great sound at speed, but a disappointing sound at idle. I also had a huffing or puffing sound, more noticeable on one side. Last winter, I pulled the iron heads off, had them completely rebuilt and put it back together. The mid-range sound is the same, but the sound at idle is much better, even with my mild cam. Trouble was that I had a lot of recession of valve seats and wearing away of the valve faces to where there was almost no margin. New seats and several new valves helped. In the end, I probably could have gotten about the same results for a little more money with new heads, but I wanted to keep the ones I had.