Used Mansfield 8011

[Jason Dempsey]

You will run into a few issues by extending the chimney out so it clears the eave. To start with, having a long horizontal run is less than optimal. I'd much rather have a set of 30 degree elbows than 30" of horizontal pipe.
You need someway to attach the Tee support, most are adjustable but only out 8"-10" or so.
You will find the same issue with your wall bands used for vertical bracing. They adjust but not enough to miss your eave. But these can be custom made pretty easily.
Excel makes a Tee support and wall bands that are adjustable enough to do what you want, but its pricy stuff! This is going to be your best option unless you custom make your supports.
http://www.icc-rsf.com/main.php?t=chem_produits&i=12&d=&l=en

Thanks Webby ... I think I'm going to try to cut through the overhang afterall.