Oooof. I hadnt thought of that.That's perfect! THANKS!! The factory one a well-known North Cali saw builder is selling has identical factory ports,one on each side of muffler.I've only seen a handful of factory dual ports,less than 10 in a lot of years time. Still too high priced IMO,even for a rare OEM part that was discontinued years ago. Gonna look for the deflector now,buy it if available,then wait to drill the port AFTER it arrives,just in case. Do I need an extra screen/spark arrester also? Existing muffler still has one I believe.