Scorpionjack,
Thanks for the suggestion, I'll have to give the 12 x 7 a try the next time I have the plane out. I have already pulled the baffle out of the stock YS .63 muffler, but I will have to see if the space on my plane will allow a larger header and muffler without extensive surgery. As it is, the stock muffler is totally inclosed in my cowl and up against the firewall.

Thanks again,

Lee