I would like to install an Appalachian 4N1XL in my wood burning fireplace. The pipe opening on the insert is 8" diameter. The current opening in the damper area is around 6". Sure, prefer not to modify damper area for an 8" pipe. I was thinking of using a 8 to 6" reducer at the insert and then connect a 6" pipe to it and then the liner. Anybody used a 6" liner with the Appalachian 4N1XL? Any draft issues? Thanks!