OK, I was going to wait until I was a little further along to start posting pictures of my "New Old Frenchtown Flyer" '40s era dirt track racer with a DOHC inline 8 Duesenberg. Why don't you do what I did - make an aluminum alloy 'DOHC' valve cover that fits over a stock 300 Ford six. That way you can have the look of a classic oldies racing engine with the reliability and ease of maintenance of a modern six.
I will take some photos in a few days to show you what is possible.