We took the flange into account when we measured and positioned it. We will trim it off after we determine it's final location. We need to trim the door opening too. Once it is all in place we will mark all the areas where it needs trimmed with a sharpie then take it off and trim everything. I don't think we are going to cut it all the way back as is shown in the manual. I think we may leave a bit of that front edge, but it won't overhang the firewall and probably will be just a little short of it. It looks like Wayne left a bit of that flange on his. I haven't dug through the threads to look at others to see how much, if any, they have left.

Larry