RG,
Gary and I were messing around with Feldons calculations through PM this morning, and Feldons suggests a 4"x15" stack. I'll request a 16" given the slight bend, and that would be 16" height from top of CC. When I entered my pit dimensions, I sized the firebox to 100%... And to your point, the idea is to get rid of as much bend as I can.
I also plan to have the stack entrance halfway between the grate level and top of CC.
I have considered adding some additional intake openings on the pit, but will make the decision once I get the stack modified and have a chance to check everything out. Process of elimination and trial and error. My thoughts are that I could *maybe* benefit from having openings both under the grate as well as further up the FB. But we'll see if those are necessary. Those are at least something I can do myself later on without having to weld.
Thanks guys.