port shape
 

Ok, I am looking at headers for my 75 350 cu.in. questions are primary size and I said or wrote down 1 5/8 inch, collector size at 2 1/2 in, but port shape I am assuming is round as opposed to oval and definitely not a d shape. Am I correct? At this point I am looking at patriot block hugger headers , block hugger due to the fact I would like to put the 69 style side pipes on it.