Good day everyone. I recently received a used pellet stove insert and am planning on installing it in my fireplace. I have a few questions regarding the venting as well as metal flashing around the stove itself. My current chimney is 8" round, can I get an adapter to go from the 3" exhaust to the bottom of the 8" chimney. Also the plan is to frame a box inside the fireplace and line it with sheetmetal as a heat shield. Any help is greatly appreciated.