Going off of the Olds article, Do you know what Olds oiling mods have been done?
Another thing from the article, is the divider between the center exhaust ports on the heads. It doesn?t meet flush with the header flange and has a gap from port to port. They fill it in and grind it to have a nice flat area for the exhaust to hook up to.
I don?t think he gets on here to much anymore, but 69 Kona had a pretty good running Olds. Maybe send a pm and see if you can pick his brain.