Originally Posted by kringold
The heads are installed. I can't pour anything anywhere. What I am doing is, I kinda got ripped off on some headers. They don't fit the stock motor mounts, which I didn't find out until installing them, and they have the round ports vs. the rectangle. So I decided to design some myself, and possibly build them when I take my refresher in TIG. So I need the width and height of the ports.
I see. What I might suggest is to get a set of exhaust gaskets and put them up to the heads to determine the size needed. Headers can be oval or rectangular where they meet the head. Headers are usually larger than the port outlets of the heads themselves. As long as the header inlet is larger than the head outlet things are good to go. (the step is said to stop reversion).
You could also make a paper pattern of one port by holding a piece of paper over the open port and then rubbing your finger on the edge of the metal to make an indentation in the paper. That would give you an exact pattern to measure directly from the paper.
Unless you are adventuresome, I would suggest purchasing a set of headers for your specific application.