Charlie did indeed grind on a Magnum & my “J” head for me to copy myself after I get my garage up and running. He also did do a set of race W2 heads. Flowed on a 4 inch bore plate to 323 cfm - IIRC.
Charlie is doing research and development on a 318 head for David Vizard’s “Mission Impossible” 318 project he took over from Uncle Tony. YouTube both of these names for further information on the project.
Off hand, I don’t know what the latest cfm topped out at or the flow curve to the 318 head. Do note the small valve size. Also on that note, I’m not sure what exact 318 head he has. It is an open chambered head.
Here is a link to one of Charlie’s videos. It’s a bit of a tech video. If your not into the tech side of porting and you just want to see some flow numbers of this head, fast forward some and you can see how the head flows at many points including cam lifts that 99.9% of you guys would never go.