Primary size and length on SC engine

all of those numbers are in square inches I just didn't take the time to indicate it. the tube sizes are all ID I subtracted for the 16gauge material. The 2.5 came form an average of gaskets sizes I found on line because I don't have the heads in front of me. I fudged the radiuses because I didn't want do the math on 4 corners that small. so I am thinking I have it correct.
Thanks for your help 69MOPE!