I'm rehearsing the liner installation, and there's a problem with the topper. As expected, it consists of top plate, clamp, storm collar (bought together as a kit), and raincap. These are all Heat-Fab's parts. Problem is, the clamp is too wide and doesn't fit under the storm collar, where it belongs. The supplied instructions don't even mention the clamp. Which means the liner weight is unsupported from the top. I called the dealer and asked what they recommend. He said DEFINITELY use the clamp (which I agreed with), and there will be approx. 2" airspace between the collar and the top plate. Stuff the space between the liner and the top plate hole with rock wool, to "seal" the top. Now that seems like a pretty cheesy solution to me, and noone in town has rock wool in stock either. I think anything that stops the storm collar from sitting flush against the top plate (as it is designed to do) is a bad idea. So, the other choice is to put the clamp above the storm collar, which isn't pretty but lets the storm collar do it's job and does provide SOME load bearing up there. Which do you think is best?