Am doing my own insert install of a Quad 5100. Have the liner insulated (except the last few feet at the top) and installed, and it's ovalized and through the flue.....but I'm have a couple of fitting problems. The liner is so long (35 feet, only 2 or 3 feet of which will be taken off the top when the rain cap goes on) and the roof so steep and chimney so high we're having a problem lifting the liner up and down for final fitting of the length, it's too heavy and can't get enough leverage on it to move it up or down especially with the liner ovalized through the flue....so we are just trimming from the bottom........but since the liner has been distored by being ovalized to get it through the flue we are having problems fitting it to the appliance connector and lined up correctly with the insert......is that just trail and error? Moving that insert is so rough I want to minimize the number of times we shove it in and pull it out.