I've went back to the local amish shop and checked out the rigid liners. I'm going to go that route, which will come out around 450.00 before insulation. The liners are 22 gauge 304 stainless and are very heavy. For the price I can't beat it and I'm sure it will last a lifetime. My clay liner is damaged at the top so I am having a chimney cap made to go over the brickwork to seal out the weather. I'm going to have 2 sections of pipe entering the tee so I have room to work around the ductwork behind the opening of the chimney. It will take about 2 weeks to get the custom liner. While I am waiting I will tear out the thimble and rebuild it. I'm going with a 5.5" liner to make sure I have room for the liner and insulation. Should I use 3 or 4 rivets to connect the sections together? Thanks.